and Laboratory Methods. 1333 



Leger, who worked on Sporodinia six years ago, found that both gametes con- 

 tain hundreds of small nuclei which become scattered in the mingling cytoplasm 

 after the membrane separating the gametes has broken down. Double staining 

 showed two kinds of nuclei, smaller ones near the periphery and much larger 

 ones nearer the center. At a later stage, all the nuclei disappear and at each 

 pole of the zygospore a spherical mass, the "embryonic sphere," is seen, each 

 sphere containing a large number of granular bodies. These spherical masses 

 increase in size and fuse with each other, and soon afterward numerous nuclei 

 again appear, which pass into the germ tube as the zygospore germinates. 



The present writer also finds a large number of nuclei in the zygospore, and 

 finds that the nuclei are more numerous at the periphery, but there are also 

 many nuclei in the center and all of the nuclei are approximately alike in size. 

 This condition persists for a long time, and subsequent stages were hard to 

 follow. No fusion division or disorganization of nuclei could be established 

 with any certainty. On germination the nuclei appear in greater numbers in 

 the germ tube. The presence of " embryonic spheres " is regarded as doubtful. 

 Although the writer was not able to observe any fusion of nuclei, he believes 

 that a fusion of the nuclei at the center of the zygospore is very probable. 



c. J. c. 



Davis, Bradley Moore. Nuclear Studies on This work was undertaken with the 

 Pellia. Annals of Botany, IS: 147-180, object of extending our knowledge of 

 pis. lo-ii, 1901. ^j^g cytology of the Hepaticae, and with 



the hope of throwing some light on the morphological relationships between the 

 various manifestations of kinoplasm. Three phases in the life history of the 

 plant were examined, namely, sporogenesis, the germination of the spore, and 

 the vegetative activities in the seta. In the spore-mother-cell the spindles are 

 developed in the same fashion as that which prevails in the spore-mother-cell of 

 the Pteridophytes and pollen-mother-cells of Spermatophytes. In the stages of 

 spore germination, asters with centrospheres were observed in the prophase. 

 These, however, appear to be transitory structures as they disappear before the 

 daughter nuclei are formed. In the vegetative cells the type of spindle forma- 

 tion is essentially similar to that described by Hof and Nemec for the vegetative 

 cells of the flowering plants. Davis also states that " it is probable, of course, 

 that there is likewise a blepharoplast at the time of spermatogenesis." He con- 

 cludes, however, that the kinoplasmic fibrillae, the centrospheres and kinoplasmic 

 caps are all secondary developments from the primal granular protoplasm, which 

 is the only form of kinoplasm in any sense permanent in the cell. 

 Chicago. • A. A. LawsON. 



.,..„,., J- TT , u , • In this paper Noll takes up again the 



Noll, F. Ueber die Umkehrungsversuche mit ^ <=> 



Bryopsis, nebst Bemerkungen iiber ihren much discussed subject of polarity 

 zelligen Aufbau (Energiden). Bar. d. among marine algae. Beginning with 

 deutschbot Gesell. 18: 444-451, 1900. * °. . 



the statement that m Bryopsis miiscosa, 



on which he worked, the polarity was as pronounced as in Piniis, he gives us 

 some interesting results of his experiments ; namely, that very few indeed of his 

 plants reversed their root and shoot pole when inverted. Measurements and 



