BOTAISTY. 17 



as well lis tadpole.s and some iwimature fish. The killing point of the different sub- 

 stances for these plants and animals Avas deternnned and the death point was used 

 in comparing results. 



From a careful review of the; results obtained the authoi' claims his method is reliable 

 witliin a very slight degree of variation. Of a large number of so-called poisonous 

 substances the author found that all acted in certain respects as stimulants. The 

 metallic salts were found to drive the carbon dioxid from the carbonates in the cell 

 sap. This pseudorespiration is in many cases as active as the real respiration of the 

 plant. It was found that carbon dioxid would be given off from the filtered sap of 

 crush-'d Elodea nmch more raiiidly than from the same plant without injury. The 

 stinuilati(in of potassium salts was found to be greater than that (jf sodium salts in 

 about the proportion of their relative toxicity. There was no constant difference 

 found between the chlorids and nitrates. The excessive evolution of carbon dioxid 

 under the conditions of the experiment is considered a feature in the death of the 

 plant. Just when the plant begins to die is hard to determine, as the cells in a single 

 leaf do not all die together, and dead cells may become conspicuous, while a large 

 part of the plant is still evidently alive. The evolution of carbon dioxid may 

 continue after the plant, as judged by its physical appearances, would be called dead. 



Tlie occurrence of spherulins in plant families, L. Petit ( Compl. Rend. Acad. 

 Set. Paris, 135 {190J), No. 2.3, pp. 991, 903). — The author has given the name spher- 

 ulin to certain substances which exist in chlorophyll cells of leaves of plants, l)eing 

 present as minute globules which are strongly colored by a tincture of alkanna. He 

 has investigated a large number of families of plants to determine the presence of 

 this substance and arrives at the conclusion that it is of rare occurrence among the 

 families of Apetahe and monocotyledons. 



Experimental studies on inulase, A. L. Dean \Bot. Gaz., 35 {1903), No. 1, pp. 

 24-35). — A study was made of the inulase of Aspergillus and Penicillium to discover 

 whether or not it was identical with the inulase of artichokes reported by Green in 

 1.S88. Pure cultures of Aspergillvft luger and Penicillium glaucum were obtained and 

 comparisons made with inulin prepared from Dahlia by alcoholic precipitation. The 

 method of obtaining preparations of inulase is described at length, as well as the 

 influence of various factors on the activity of the enzym. The author was able to 

 confinn the presence of inulase in these molds, and as the enzym of these fungi does 

 not pass into the culture medium it is to be classed as an endoenzym. Inulase acts 

 most vigorously in a medium slightly acid, the enzym being destroyed l)y 0.01 nor- 

 mal sulphuric acid. Alkalis hinder its activity, 0.0001 normal potassium hydroxid 

 being injurious. The optinu;m temperature for the action of inulasi' wmh found to 

 be al)Out 55° C. 



Influence of formaldehyde on the growth, of some fresh water alg-ge, R. 

 I50UILHAC {Compt. Rend. Acad. Set. Paris, 135 {1902), No. 26, 2)p. 1369-1371).— The 

 effect of adding formaldehyde in weak solution to a culture medium in w hicii Nostoc 

 jinnctiforme and Anab^'na sp. are grown was investigated, from whicli tlie author 

 <lecides that formaldehyde may serve as a nutrient for these alga> and that a certain 

 amount of light is necessary to permit them to polymerize the formaldehyde. The 

 limit of the amount of light required is very nearly that which is necessary for ])lants 

 to decompose carljon dioxid of the air. 



The motility of Rhizobium mutabile, A. Bchneider {Bof. <laz., 35 [1903), No. 

 I, pp. 56-58). — In the previous communications of the author in relation to this root 

 tubercle organism he has stated that it was absolutely nonmotile, ])ut rect^nt events 

 have caused a review of this subject in which the organism was grown on a mimber 

 of different kinds of media and it was found that it was nonmotile in most neutral 

 media, but was decidedly motile in acid media, whether the media were liquid or 

 solid. The motile forms are much smaller and more nniform in size than the 

 nonmotile ones. 



