BOTANY. 021 



of nickel and cobalt as shown upon the germination of wheat are reported, from 

 which it ajipears that the toxicity of the same compound of each metal was very 

 nearly the wime, and both are quite high. 



On the poisonous properties of compounds of silver, mercury, gold, plati- 

 num, and palladium, -when applied to higher plants, II. Coupin {Chmjil. Rend. 

 Sac. Biol. Parix, oS (moi), Xo. 17, pp. 509,510). 



On the toxic value of mercuric chlorid and its double salts, J. F. Clark 

 {.Tour. I'hi/.^. Clwm., 5 {1901), No. 5, pp. 289-316). — The author made an extended 

 study of the inliuence of various solutions of HgCl, on fungi. The results are reported 

 in a table and also plotted. The results of the addition of NaCl in varying amounts 

 to the HgCl.2 is also noted. In great concentration of these 2 salts, a large increase in 

 the toxic properties of the mixture was obtained by the simple dilution with water to 

 4 or more volumes. The reason for this would appear from the fact that by the greater 

 dilution the double salts were more readily l)roken down. Contrary to the usual 

 belief, the addition of NaCl to the mercuric salt lessened, instead of increased the 

 toxic value. This is stated to be because of the fact that the double salts have less 

 attinity for the proteid substances than the pure HgCl.^ solution. 



Digestive secretion of Nepenthes, Clautkian {Biol. Centhl., 21 {1901), p. 38; aJ>s. 

 in .Tour. Roy. Micros. >Soc. ^London}, 1901, No. 3, p. 290). — The result of a series of 

 observations on the digestive properties found in the urns of Nepenthes are given. 

 Owing to the comparative scarcity of small insects no great numbers were entrapped. 

 The bodies of those that were captured were found more or less completely digested, 

 and, according to the author's experiments, bacteria had no part in the digestion. 

 The fluid in the urns is ordinarily neutral to reagents, but upon shaking or introduc- 

 ing any foreign sulistance it becomes acid. The digestive ferment present is consid- 

 ered to be zymase, which is regarded as a pepsin rather than a trypsin. 



The oxidases in higher plants, N. Passerini [Ahs. in Ann. Agron., 27 {1901), 

 No. 6, p. 302). — The author has made a study of the diffusion and localization of 

 oxidases among the higher plants, as shown by the well-known reactions for diastases, 

 such as hydroquinone, pyrogallic acid, and tincture of quaiacum. He found that 

 oxidases are widely distributed among plants, the Solanacete, Labiatpe, Composita?, 

 and Uinbelliferffi containing them in considerable abundance. Diastases are most 

 noticeable in the roots of plants, and rarely in the leaves. When present in the 

 leaves it is most often localized along the veins. The pistils and filaments of the 

 stamens are richest in oxidases of the tiowering organs. They are also localized in 

 the pericarp of the fruits. Seeds in the process of formation contain oxidases, but 

 they disai)i>ear with their ripening. Aquatic plants do not seem to contain oxidases. 



Enzyms of fungi, P. Kohnstamm {BoL Centbl. Beihefte, 10 {1901), pp. 90-121; 

 aba. in .Tour. Roij. Micros. Soc. \_London], 1901, No. 3, p. 308). — An extensive study 

 has been made with enzyms which attack starch, glucosids, proteids, and cellulose in 

 those fungi which are noted for destroying wood, especially in Agarirus melleus, 

 ATernlins hichrnnuinr, and Poli/jxiriis .^(jiKiniosus. The mode of treatment is described 

 at length and the results summarized. From the 8 fungi enumerated a starch- 

 destroying enzym (amylase) was obtained which apparently is identical with the 

 diastaticenzym of malt. It was found most abundant in Poh/jjorits .^trpuanosiis. Emul- 

 sin, a glucosid ferment, was found in .^f. lafhri/nians and /•*. sqiuimosKs, but not in 

 .1. melleus. A proteolytic enzym was found in small quantity in A. melleus, and more 

 abundantly in the others. In M. lachrymans a cellulose-decomposing enzym was 

 found, and it was established that these various ferments may act sinmltaneously. 

 The ferments were found only in the receptacli' of /*. .^(/udmosus, while the mycelium 

 of M. Idchri/iniins also containeil these sul)stanc('s. 



Decomposition of glucosids by mold fungi, A. IiurxsTKiN {Bol. Centhl., 

 Beihefte, 10 {1901), p]>. 1-50; ahs. in .Tour. Roi/. Micros. Soc. [London], 1901, No. 3, 

 p. 310). — A series of exi)eriments are reported on the decomposition of different 



