while hydrochloric acid dissolves the raphides without effervescence, proving them to be calcium oxalate. The fibres are proven to be lignified from their reactions with phloroglucin and hydrochloric acid, also with aniline sulphate and sulphuric acid. Treated with iodine and sulphuric acid a reddish-yellow color is produced, which confirms the above statement. Knowing that these fibres are hard-walled, lignified cells, and that they appear scattered through the parenchyma, they may therefore be placed among the sclerenchymatous tissues. Similar cells to the above, occurring in Aroideæ, Rhizophoraceæ, Nymphæaceæ, and especially those found in the leaf lamina of Monsterineæ, are termed "internal hairs" by de Bary. Concerning them he says:1 "Numerous hairs are contained in the cavities and passages of the lamellar parenchyma. * * * * They closely resemble sclerenchymatous fibres and were therefore first described as 'bast cells' by Schleiden." Farther on he makes the statement that hard-walled hairs are fundamentally related to sclerenchymatous fibres in every respect and are special cases of the latter, distinguished by form and distribution. On taking longitudinal sections from various parts of the plant, the fibres are found to occur in every part. But in no part are they found in so great numbers nor so perfectly developed as in the exocarp or outer portion of the fruit. Here they resemble true bast fibres, with but little branching, while in the leaf lamina and spathe, especially, they are very slender and variously branched, filling the interstices of the surrounding tissue and resembling the "internal hairs" described by de Bary. For a general description of the fibres it may be stated that the walls are very evenly thickened, possessing no projections nor characteristic markings. They are firm in texture but not brittle as wood fibres. In length they are from .9 mm. to 1.6 mm. ; in diameter from .015 mm. to .03 mm. Their contents are similar to those of the surrounding cells, but slightly granular. They occur in the parenchymatous tissue situated in the interstitial or intercellular spaces. While the fibres differ much in size and assume a variety of shapes, due mainly to their promiscuous branching, we find the raphides to be of nearly uniform size and form. Like the fibres they occur throughout the plant in the parenchymatous tissue, but most abundantly in the fruit. Here 1 Comp. Anat. of Phanerogams and Ferns. they occur in countless numbers. Lying parallel with one another, they form compact bundles which are situated in narrow elongated cells, known as crystal cells. The raphides are very minute; in length from .or mm. to .012 mm.; in diameter about .002 mm. They are many sided, with angles and faces poorly defined, and possess sharp ragged ends. In addition to raphides, isolated stellate crystals are also found in the fruit of Monstera. Concerning the early developement of fibres, de Bary states that they arise by early outgrowth of a cell of the wall of the cavity (usually one layer of cells thick), which remains relatively narrow so as to form long, pointed arms. This explanation may be accepted as general, but it has not been satisfactorily proven in this special plant. Finally, we may draw the conclusion that since the raphides are so minute, and form such a small quantity compared with the fibres, and since the action of calcium oxalate is very slight, the peculiar sensation caused by placing a piece of the outer fruit in the mouth must necessarily originate from the mechanical action of the sharp-pointed sclerenchymatous fibres, and not from any chemical action of the raphides. Purdue University, Lafayette, Ind. EXPLANATION OF PLATE X.-Fig 1. Fruit of Monstera deliciosa. Fig. 2. Section of fruit showing structure; a, endocarp or core; b, hexagonal segments or fruit proper; x, mesocarp or edible portion; y, exocarp. Fig. 3. Exocarp dissected under low power; a, fibers, b, raphides. Fig. 4. Fiber and raphides under high power. Fig. 5. Cross-section of "fruit proper;" a, cross-section of fibre. Fig. 6. Longitudinal section of "fruit proper;" a, crystal cell; b, parenchyma cell; c, fibre. Our worst weeds. BYRON D. HALSTED. It is due to those who have already aided me in the study of the weed flora of the United States that some preliminary report be given. The first twenty-five lists which have been received contain in all 267 species, and represent 14 states, ranging from Massachusetts to California, and Wisconsin to Texas. As, in the present article, we are to deal with the worst weeds, attention will be confined to those which appeared at least five times in the lists. Of these there are 34 species, which will be enumerated below. To those who may not have chanced to see the kind note of the editors of the GAZETTE (xiii. 327), setting forth my wishes, it may be said that the call was for at least the twenty worst weeds in any locality or territory which any one would be pleased to report upon. In nearly all instances the weeds were given their rank as to injuriousness, and from such re. ports the present article is made up. Following each species will be observed a fraction: the numerator indicates the number of times the species appears in the twenty-five lists, while the denominator is the sum of all the rank numbers. 66 Thus, Agropyrum repens has the fraction, which indicates that this quack-grass or quick-grass" appears eight times in the twenty-five lists, and that the rank total is thirtyone, the respective ranks being 5, 1, 4, 3, 9, 2, 5, and 2. Ás another illustration, Chrysanthemum Leucanthemum, or "ox-eye," "ox-eye daisy," or "bull's-eye," also has eight mentions, but the sum of the rank figures, 4, 16, 17, 9, 5, II, 6, 12, is eighty. It will be seen that the fraction following each species therefore indicates the rank of the injuriousness of each sort, as far as averages can do it in connection with the wide or limited distribution of the species. The thirtyfour are as follows, arranged alphabetically: The numerators may fairly indicate the prevalence of the weed. Thus Portulaca oleracea, the common purslane or "pusley," has the most frequent mention, namely, 20 out of the 25; while Solanum rostratum, the Texan nettle or beaked horse-nettle, is only five times reported in the list, but is a vile pest moving northward and eastward, and if not checked in its course will bring dismay to thousands of farmers who now know nothing of its pernicious habits. The interested reader can quickly select from the table the species which are most prevalent over the whole United States, but the relative injuriousness, which is obtained by dividing the denominator by the numerator, is not so easily seen. The following list of 20 is therefore given in the order of injuriousness, beginning with the worst: Cnicus arvensis. Xanthium stramonium. Rumex Acetosella. Ambrosia trifida. Setaria glauca. Chenopodium album. Panicum Crus-galli. Capsella Bursa-pastoris. Cnicus lanceolatus. Arctium Lappa. The writer is anxious to add to the number of his reports, and will be pleased to hear not only from every state and territory in the Union, but in such numbers that the summary derived from them may furnish a basis for future calculations, if not for national legislation. Questions of eradication, quarantine and the like, come naturally after the nature of the pests has been settled upon in the broadest sense. The greater part of this work must be done by local observers who are willing to aid in arming ourselves as a nation against a vast array of active enemies to American agriculture. If any one will add to or take from the list of 34 species herein given, let him do so as a bit of public ser vice. New Brunswick, N. J. Sweet Cassava (Jatropha Manihot.) H. W. WILEY. About the middle of March, last year, I received from Mr. R. H. Burr, of Bartow, Fla., a package of cassava These roots reached the department in fine condition, being apparently as fresh as the day they were taken roots. from the soil. After careful sampling and cleaning a sufficient quantity of the roots was cut into thin slices and thoroughly dried. In a definite weighed portion, sampled as carefully as possible, the percentage of moisture was determined. The dried and powdered roots were preserved for future analysis. Owing to a press of other matter this analysis was not made until the latter part of July and the first of August, 1888. Mr. Burr, in forwarding the roots, sent the following information concerning them: "The roots do not last long after digging, drying up or rotting. Since this variety of cassava is not the bitter or poisonous kind, it is generally known in Florida as the sweet cassava. The roots are fed to all kinds of stock in a fresh state and are greatly relished. It has been sufficiently tested here to show its great value as stock food. The yield, under favorable conditions, is astonishing. I have recently dug one plant of one year's growth which weighed fifty pounds, being at the rate of more than 1,500 bushels to the acre. Eight hundred to one thousand bushels per acre can be confidently reckoned on." The roots received by us were long and slender and of various sizes; some of them were quite two feet long and weighed several pounds. The bark, which contains a poisonous principle if any be present, was carefully scraped off and has been preserved for subsequent examination. The analysis of the sample calculated to dry substance, is given in the following table: Serial No........... Ash............ Oil (petroleum ether extract)........ Ether extract (glucosides, alkaloids, organic acids, 5547 1.94 per cent. .74 Alcohol extract (amids, sugars, resins, etc.)......... 17.43 Starch........ Albuminoids (calculated from nitrogen).. 4.03 71.85 3.47 100.73 In regard to the method of analysis little need be said it was carried on in accordance with the well-established rules of plant analysis as laid down by Dragendorff. The first extraction of petroleum ether gave the fat or oil alone, and the subsequent extraction with sulphuric ether gave the glucosides, alkaloids and organic acids. That portion of nitrogen existing as amids has been estimated in the alcoholic extract. The total nitrogen was also estimated and entered as albuminoids; a small portion of the nitrogen has thus been counted twice in the total results which add up a little over 100. A characteristic feature of the cassava root is shown in the large amount of substance present soluble in |
