ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 477 



cation with one another by protoplasmic connections. Even the sieve- 

 tubes, with their conducting cells, are connected in this way with the 

 surrounding cambiform, both in Viscum and in Cucurbita Pepo. No form 

 of tissue constitutes a protoplasmic system in itself ; in the whole of the 

 plant the protoplasts are in connection with one another unaffected by 

 the limits of the tissues. The thickness of the protoplasmic connections 

 is, in Viscum, nearly uniform for all the cells ; in the pits their number 

 is about 130 for every square fx. As a rule they occur only in the pits, 

 though they are found, in Viscum, in the unpitted walls between sieve- 

 tubes and conducting-cells. The largest number of pits, and conse- 

 quently of protoplasmic connections, occurs in elongated cells, such as 

 those of cambiform or of the medullary rays, and on the transverse 

 walls at right-angles to their longer axis. No certain evidence was 

 obtained of a secondary formation of protoplasmic connections. 



Changes in the Cell resulting from Fermentation.* — From obser- 

 vations made on the gourd, Cucurbita maxima, MM. L. Matruchot and M. 

 Molliard record the following as the chief changes which take place 

 in the cells themselves as the result of fermentation properly so-called : — 

 The nucleus assumes a very light colour from the partial disappearance 

 of the chromatin, the portion which remains being located in the peri- 

 phery of the nucleus ; the protoplasm becomes greatly vacuolated, and 

 in its interior are formed a number of drops of an essential oil. This 

 latter process appears to be a constant result of fermentation. 



Cell-Changes in Drosera.f — Herr 0. Eosenberg publishes the result 

 of a series of observations on the cytological changes produced in the 

 cells of the tentacles of Drosera rotundifolia through the influence of 

 various food-materials, as well as on the phenomena of cell-division in 

 the various tissues, vegetative and reproductive. 



In the vegetative cells the spindles are developed from caps of kino- 

 plasm, and in the pollen-mother-cell the presence of a delicate zone of 

 granular kinoplasra and fibrillas encircling the nucleus indicates the 

 beginning of the formation of the chromatin part of the nuclear figure. 



The food-materials employed were very numerous : — Albumen, pep- 

 ton, flesh, cheese, sugar, bread, haemoglobin, and other organic substances ; 

 borax, calcium nitrate, calcium phosphate, ammonium oxalate, &c. 

 Feeding the leaves with orgauic material brings about very shortly 

 changes in the cytoplasm and nucleus of the epidermal cells of the 

 tentacles. Peculiar granules appear in the cytoplasm near the nucleus, 

 and the tannin vacuoles become more prominent. The chromatin 

 of the nucleus increases greatly in quantity along the linin-network, 

 and finally collects as longer or shorter rods on the membrane. The 

 chromatin finally takes the form of a thick thread, and the linin-net- 

 work cannot be followed. During the process of feeding, the nucleole 

 usually grows smaller until it becomes very insignificant, but there is 

 no fixed relation between the decrease in the size of the nucleole and 

 the great increase in the amount of chromatin. Other cells in the 

 tentacles are affected in the same way, those of the endoderm and stalk 



* Comptes Rendus, cxxx. (1900) pp. 1203 5. 



t ' Phys.-cytol. Unters. iib. Drosera rolundifolia,' Upsala, 1899, 126 pp., 2 pis., 

 and 6 figs. See Bot. Gazette, xxiv. (1900) p. 294. 



Aug. 15th, 1900 2 K 



