Morphologie, etc. — Palaeontologie. — Algae. 83 



thread is loosely coiled. The cells are separated from each other 

 and from Ihe tapetum by delicate plasmatic membranes. The tape- 

 tum at first consists of two layers of cells but, at the close of the 

 first prophase, these have recolted in a common tapetal Plasmodium. 

 As the prophase advances the thread becomes thicker by longitu- 

 dinal contraction and, later on, Segments into the chromosomes, 

 which, at first, show clefts that have evidently arisen from longitu- 

 dinal fission; some are bent or doubled in various degrees. The 

 author concludes that the bent chromosomes are, or become di- 

 vided, by transverse fission at the apex of the bend, and that the 

 Separation at anaphase takes place by this transverse fission. The 

 longitudinal division begins in early prophase, is lost sight of or 

 only slightly indicated at metaphase, and completely disappears at 

 anaphase. Soon after chromosome formation the nuclear membrane 

 becomes fibrillar and fine threads appear in the nuclear cavity; the 

 fibrils become more pronounced and begin to press out to form the 

 multipolar spindle. Meanwhile the cytoplasm becomes less dense 

 and has evidently contributed substance to the growth of the spindle. 

 Later, the several poles collect at two opposite points and form the 

 bipolar spindle. It is suggested that the force which causes the dif- 

 ferentiation of the spindle emanates from the nucleus and particu- 

 larly from the chromosomes. The chromosomes are apparently drawn 

 to the poles by contraction of the fibres. No cell plate is formed 

 between the resting daughter nuclei but in its place is a broad 

 dense band of cytoplasm. The formation of the spindle in the second 

 division resembles the process in the first; the prophases are ra- 

 pidly completed. Before the granddaughter nuclei are formed the 

 band of cytoplasm laid down in the equator of the first division is 

 transformed into kinoplasmic connecting fibres; cell plates are then 

 formed demarking out the spores. A gradual transition now takes 

 place from the filar kinoplasm to the alveolar trophoplasm. The ki- 

 noplasm and trophoplasm are mutually independant, one increasing 

 at the expense of the other as the requirements of the cell demand. 

 The tapetal Plasmodium flows in between the mother cells and its 

 nuclei accumulate in Spaces between the latter. As the spores de- 

 velope the Plasmodium becomes depleted; it is suggested that the 

 nuclei influence the nutrition of the spores at the cost of the Plas- 

 modium. M. Wilson (Glasgow). 



Berry, E. W., A Review of D. H. Scott on The Present Po- 

 sition of Palaeozoic Botany. (Torreya. VII. p. 62—64. March 1907.) 



In reviewing Sc Ott 's paper, the author makes it the basis for 

 strongly emphasizing the idea now gaining strength among bota- 

 nists, that the divorced relations hitherto existing between Botany 

 and Palaeobotany have no valid basis in fact, and that henceforth 

 the latter can have no claim to a separate Status. In all future bo- 

 tanical studies, fossil plants must of necessity be taken into account 

 in all the broader discussions of morphology, systematic botany and 

 geographical distribution. D. P. Penhallow. 



Collins, F. S., Notes on Algae. VIII. (Rhodora VIII. August [Sep- 

 tember 3]. p. 157—161. 1906.) 



Notes on Gohia Baltica (Gobi) Reinke, which is known in Ame- 



