80 



SCIENCE. 



[Vol. I., No. 3. 



BOTAKTT. 



(Struciu7'al and physiologicaU) 



A general method for examining vegetable 

 tissues. — E. Fremy has contributed uiucli to our 

 knowledge of the celhilose group of organic sub- 

 stances. In a paper hitely republished, he has brought 

 together the more important reactions presented by 

 the members of tlie group, and has followed this by 

 a memoir in which M. tjrbain has assisted. From 

 both papers the following results are now summarized. 

 The substances which form the skeleton of pl.ants 

 are principally pectose and its derivatives, cellulose 

 and its isomers, vasculose, and cutose. Pectose acted 

 on by alkaline carbonates is changed into pectates. 

 These are decomposed by hydrochloric acid, which 

 throws down gelatinous, insoluble pectic acid. Cel- 

 lulose and its isomers agree in being readily soluble in 

 concentrated sulphuric acid, but differ in the follow- 

 ing points: cellulose dissolves at once in cuprara- 

 monia; paracellulose, only after the action of acids; 

 metacellulose, not even then. Vasculose is not easily 

 soluble in concentrated sulphuric acid, but, after the 

 action of oxidizing agents, forms resinous acids separ- 

 able by alkalies from associated cellulose. Cutose, 

 the transparent membrane covering the aerial organs 

 of plants, is dissolved neither by concentrated sul- 

 phuric acid nor by cuprammonia; but it dissolves 

 rapidly without change in dilute alkaline liquids. 



Following the facts above summarized, the authors 

 give results of their analysis of different organs of 

 plants, a few of which are herewith given: — 



Root of Paulownia. — 1°. Substances soluble in 

 water and in dilute alkalies: cork 45, soft bast 56, 

 body of root 47. 2°. Vasculose: cork 44, soft bast 

 34, body of root 17. 3°. Paracellulose : cork 4, soft 

 bast 4, body of root 30. 



Stems. — Vasculose increases in amount with den- 

 sity of the wood. The pith contains of cellulose 37, 

 paracellulose 38, vasculose 25 per cent. Cork con- 

 tained: matters soluble in acids and alkalies 5, cutose 

 43, vasculose 29, cellulose and paracellulose 12 (cu- 

 tose and vasculose forming together the suberine of 

 Chevreul). 



Leaves of ivy. — Water and substances soluble in 

 neutral solvents 707.7, parencliyma (formed of cel- 

 lulose and pectose) 240, fibres and vessels (formed of 

 vasculose and paracellulose) 17.3, epidermis (cutose 

 and paracellulose) So. 



Petals of Dahlia. — Water and soluble matters 

 961. -30, parenchyma (of cellulose and pectose) 31.63, 

 vasculose 1.20, paracellulose 2.27, cutose 3.60. 



These interesting results throw considerable light 

 on some obscure micro-chemical reactions, partic- 

 ularly the behavior of tissues with cuprammonia and 

 with alkalies. With the authors' notes relative to 

 the bearing of their results on technical chemistry, 

 this notice cannot deal. — {Ann. sc. nat., boL, 1882, 

 360.) G. L. G. [228 



Fertilization of alpine flowers. — During a resi- 

 dence of several years at Grenoble, M. Musset has 

 paid attention to the relative abundance of flowers 

 and insects, finding all orders of insects well repre- 

 sented as high as 2,300 metres. Above this altitude 

 Lepidoptera, Diptera, and certain Hymenoptera pre- 

 ponderate, as Dr. Miiller and others have also ob- 

 served. Flower-frequenting insects are found at all 

 altitudes, in proportion to the abundance of ento- 

 mophilous flowers; their visits being determined by 

 several causes, the state of the atmosphere being one 

 of the most important. It is staled that the waking 

 hours of nyctitropic flowers and of insects are identi- 

 cal. — [Comptes rendus, Aug. 7.) 



M. Heckel does not attach much importance to the 



visits of insects in the evolution of the large flowers 

 characteristic of many alpine plants He believes, 

 in common with Bonnier and Flahault, that the more 

 intense solar radiation is the chief factor in causing 

 the larger size of flowers at high altitudes. — (Ibid., 

 Dec. 4.) w. T. [229 



Pollination of Rutaceae. — In a paper read be- 

 fore the Linnean society of New South Wales, on 

 plants found about Sydney, Mr. Haviland discusses 

 the protandry of Philotheca australis and Boronia 

 pinnata. The stamens are situated at first so as to 

 bring tlie anthers over the immature stigma, as in 

 other Rutaceae; this position insuring cross-fertiliza- 

 tion with Utile waste of pollen. It is suggested, that, 

 as they thus prevent the stigma from receiving the 

 maximum of light and heat, their position may aid in 

 retarding its development, and thus cause the pro- 

 tandry. — ( Nature, Dec. 28. ) w. T. [230 



Value of crossing in plants. — For a number of 

 years Prof. W. J. Beal of the Michigan agricultural 

 college has been carrying on the work of experiment- 

 ally testing the effects of cross and close fertilization 

 so ably begun by Mr. Darwin. Most of his experi- 

 ments have related to Indian corn. As was to be 

 expected, the results of no two years' experiments 

 correspond at all closely; but they all show a marked 

 gain when plants raised from seed grown some dis- 

 tance apart are inter-crossed instead of being allowed 

 to self-fertilize. The average of four years' experi- 

 ments shows the gain to be 27%. The least gain was 

 a trifle under 10%; the greatest, 51%. One year's ex- 

 periment with wa.x beans showed a gain of 136%. — 

 [Amei: journ. sc, Dec.) W. T. [231 



Vegetable fly-trap. — Potonie finds that the feet 

 of small flies that alight on the leaves of the West 

 Indian Desmodium (Pteroloma) triquetrum are caught 

 in the curves of the fine, arched leaf-hairs, so that 

 their most desperate efforts to escape are unavailing. 

 The insects captured belong to the genus Chloria. 

 House-flies, with larger feet, are not captured; while 

 ants and plant-lice have such small feet that they 

 can walk over the leaves witli impunity. The plant 

 appears to derive no benefit from the death of its vic- 

 tims, which starve to death in captivity. — [Kosmos, 

 Nov.) W. T. [232 



{Sysiemaiic.) 



Ne-w orchid in Florida. — The tropical Epid en- 

 drum cochleatum has been discovered by W. W. 

 Calkins, growing upon the live-oak, at Jupiter Inlet, 

 on the Atlantic coast of Florida. — (Coult. bot. qaz., 

 Dec, 1882.) s. w. [233 



■Western grasses, — A list, by F. L. Scribner, of 

 the grasses recently C()Jlected by Pringle in Arizona 

 and California, is accompanied by critical notes and 

 descriptions of the rarer species. — [Torr. bot. bull., 

 Oct. and Dec, 1882.) s. w. [234 



American conifers. — A popular account, by Dr. 

 George Vasey, of the distribution and characteristics 

 of the coniferae of the United States and Canada. — 

 (Amer. journ. for., Dec, 1882, and Jan., 1883.) s. w. 



[235 



The tonga plant. — The drug tonga is shown by 

 N. E. Brown to be the product mainly of a climbing 

 aroid (Epipremum mirabile, Schott), widely distiib- 

 uted through the East-Indian Islands to Australia 

 and Fiji. The plant has been hitherto involved in 

 much confusion botanically; and a full description 

 is given, with detailed synonymy. — (Journ. bot., 

 Dec, 18S2.) s. w. [236 



