Journal of Applied Microscopy. 253 



fibers. Spindle formation in the second division of the pollen-mother-cell is the 

 same as in the first. No centrosomes were observed. The writer accepts the 

 conclusion of the Bonn school, that centrosomes take no part in the formation of 

 the spindle, but does not suggest any explanation for the transformation of the 

 multipolar spindle into the bipolar. c. j. c. 



Ikeno, S. Untersuchungen uber der Ge- This important paper has been long 



schlechtsorgane und den Vorgang der Be- promised, and the preliminary notes 



fnichtung bei Cycasrevoluta. Jahrb. f. wiss. r j r j 



Bot. 32: 557-602, pi. 8-10 and 2 autotypes, have been so often quoted that it does 



9**- not seem new to connect Ikeno's name 



with Cycas. The various stages in the development of endosperm and the forma- 

 tion of archegonia correspond closely with the conditions already described in other 

 Gymnosperms. The development of the ^gg cell was traced in detail. The 

 material for its increase in volume is a half-liquid protein stuff furnished by the 

 nuclei of the wall cells and also by the nucleus of the Qgg itself. During the 

 ripening of the e.gg, a ventral canal cell is cut off. The karyokinesis concerned 

 in the cutting off of this cell appears to be of the heterotypic type. 



The pollen grain consists of two small cells, which he calls prothalHal cells, 

 and one large embryonal cell. The latter is the cell which forms the pollen tube. 

 The inner prothallial cell divides to form a stalk and generative cell, while the 

 prothallial cell is resorbed. It would seem to the reviewer that it would be more 

 appropriate to call the embryonal cell a " tube cell " and to restrict the term, pro- 

 thallial cell, to the single cell which is resorbed. Two centrosomes appear in the 

 body cell, and when this divides, each of the resulting spermatids receives a 

 single centrosome. These centrosomes, which reach a diameter of 15yu, behave 

 very much like those of Gingko, becoming drawn out into a band which gener- 

 ally makes four spiral turns and gives rise to the cilia. 



Shortly before fertilization, the e.gg cell shows a crater-like receptive spot at 

 its apex. After entering the e.gg, the spermatozoid nucleus slips out from its 

 cytoplasm, which then disorganizes within the Qgg cell. The sperm nucleus unites 

 with the egg nucleus at the receptive spot, and the fusion nucleus then presses 

 deeper into the egg, where it becomes dissolved. It will be recognized that this 

 is a peculiar and hitherto unknown type of fertilization, and one which needs 

 abundant evidence to insure its acceptance. 



The formation of the embryo corresponds closely with that already described 

 for Gingko. c. j. c. 



Jeffrey, E. C. The Gametophyte of Botry- These investigations are by far the 

 chium Virginianum. Trans. Canadian Insti- most important of recent contributions 

 tute. 5: 265-294. pi. 1-4, 1896-7. ^ ^1 u 1 r i-u /-i u- 1 



to the morphology of the Ophiogloss- 



aceae. Hitherto the gametophyte of Botrychium was little known. All attempts 

 at culture from the spores had failed to obtain more than two or three cells, and 

 our knowledge was based on descriptions of a very few chance specimens. Mr. 

 Jeffrey was so fortunate as to find over six hundred specimens at one time, and 

 has since collected more. He finds that the prothallia are tuberous in form, 

 destitute of chlorophyll, and entirely subterranean. The lower half of the game- 

 tophyte body, excepting two or three layers of cells, is infested with an intracel- 



