ZOOLOGY AND BOTANY, MICROSCOPY, ETC. f»37 



latter is the most probable, since substances like lecithin can only be 

 detected after coagulation of the albumin. The composition of this 

 compound appears to be so unstable that dissociation occurs at the 

 slightest disturbance of the protoplasts. 



Function of Nucleoproteid.* — W. Zaleski has made numerous 

 experiments as to the function of nucleoproteids in plants. The 

 investigator finds that these proteids are built un during the growth of 

 the somatic cells, and that they contain very stable formative materials 

 which usually go to build up the protoplasts ; under normal conditions 

 of growth the nucleoproteids show no appreciable decrease in quantity, 

 but under abnormal conditions, i.e. when in danger of death, they may 

 serve as a food reserve. Nucleoproteids undoubtedly break down during 

 the growth of seedlings and the differentiation of somatic tissues, but 

 the amount formed exceeds the amount used, except at the time of 

 death, when conditions are reversed. It appears that nucleoproteid is a 

 characteristic system of different compounds, not a single complex 

 substance, and it cannot be regarded either as a bearer of life or as 

 transmitting hereditary characters. The proteids of the nucleus and of 

 the protoplasm appear to be different. The chemical structure of the 

 protoplasts is unknown, but albuminoids, proteids, lipoids, and especially 

 phosphides, appear to be necessary, while stearine also is present. 

 Enzymes are combined more or less firmly with the lipoids, but upon 

 death these enzymes are set free, thus explaining the difference between 

 the ferments of living and of dead plants. 



Chondriosomes in Plant-cells.f — A. Meyer contributes some re- 

 marks upon a paper lately published by Lewitsky, in which it is stated 

 that chromatophores are developed from chondriosomes. The writer 

 points out that while Lewitsky claims that the chromatophores originate 

 independently of the nucleus and cytoplasm, the chondriosomes of 

 animal-cells give rise to such substances as yolk, pigment, fat, etc., 

 which correspond to those substances formed in the plant-cell as a 

 result of the modification of cytoplasm, and this appears to contradict 

 the view put forward. It is further maintained that difference in 

 coloration in response to certain reagents is insufficient basis for such a 

 theory, and its author is asked to state how chondriosomes may be dis- 

 tinguished, and to give stronger reasons for his opinion. 



Heterotypic Division of Pollen-mother-cells.:}: — L. v. Bonicke has 

 investigated the presynaptic and synaptic stages in the heterotype division 

 of pollen-niother-celfs, in order to form some definite opinion as to the 

 relative distribution of chromatin and linin. The plants used were 

 Equisetum, Polygonatum, Marantha, Ohelidonium, Delphinium, Sam bun's. 

 Datura, Bryonia, and HeHanthus. Some types, e.g. Equisetum and 

 Polygonatum, show a distinct net-work of linin with granules of 

 chromatin ; Datura, Helianthus, etc., have a finer net-work of linin with 

 chromatin in the form of prochromosomes, while others, e.g. Sunburns, 

 show only nodules and threads of chromatin, but no linin at all. Thus 



* Ber. Deutsch. Bot. Gesell., xxix. (1911) pp. 14G-55. 

 t Ber. Deutsch. Bot. Gesell., xxix. (1911) pp. 158-60. 

 \ Ber. Deutsch. Bot. Gesell., xxix. (1911) pp. 59-G5 (1 pi.). 



Oct. 18th, 1911 2 T 



