ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 217 



in the other direction, beyond the pole, into the protoplasm, where 

 they divide and end in the fine protoplasmic network. (_;) The 

 chromophilous balls of the equatorial plate divide in the plane of 

 the spindle axis, and the daughter segments again divide. The 

 results of this longitudinal division recede towards the poles, de- 

 scribing in so doing a turn round the transverse axis, and finally fuse 

 together to form the polar plates, (k) The spindle filaments, at first 

 somewhat convex, are stretched as the polar plates recede. The 

 protoplasm of the cell constricts, the cylindrical form is replaced 

 by that of an hour-glass, and at length complete division occurs. 



(/) In the half-moon-shaped new nucleus, rows of microsomata 

 become gradually distinct. Finally a regular coil is formed, whose 

 loops all start from one excentric point. At this point a new " ac- 

 cessory body " is rapidly budded out into the protoplasm. As it 

 becomes more defined, the coil breaks up, and is replaced by a 

 rounded off nucleus with protoplasmic membrane, nuclear network, 

 and chromatin-granules. (m) Herr Platner follows the history of 

 the " Nebenkern " still further, through the spermatocytes, to the 

 spermatides, or undifferentiated sperms. A large portion of the 

 nucleus of the spermatide goes to form the last "Nebenkern," which 

 is an irregular polygonal body like a ring compressed from various 

 sides. It persists for a time along with the spermatide remnant, which 

 clings to the side of the developing axial filament, and probably helps 

 to form the spiral membrane which envelopes the latter. 



The relative observations of other investigators are briefly 

 reviewed, and those of Gaule criticized, in regard to which Herr 

 Platner communicates the results of some further observations on the 

 " accessory bodies " of the pancreatic cells of Anguis fragilis. 



Amoeboid Movement of Cell-Nucleus.* — Messrs. S. H. and S. P. 

 Gage, in studying the blood of Necturus, find that the nucleus of the 

 white corpuscle executes distinct and vigorous movements, quite 

 independently of those of the corpuscle. The white corpuscles are 

 very large in this animal, and the observers hope, by studying these, 

 to elucidate various questions as to the membrane and division of nuclei. 



Unicellular Glands in the Epithelium of Bladder of Am- 

 phibians.f — Dr- J. H. List finds unicellular glands (goblet-cells) in 

 the epithelium of the bladder of various Amphibians [Triton, Bana, 

 Bufo, Bombinator, Hyla) ; they contain two different substances, one 

 in the form of a network which fills the theca, which may be called 

 the filar mass, and an interfilar mass which lies between the cords 

 and is apparently homogeneous. The filar mass consists of thin 

 apparently homogeneous cords, which form polygonal or rounded 

 meshes ; the nucleus is always found at the base of the cell, and 

 appears to be in no case directly connected with the filar mass. The 

 interfilar, unlike the filar, takes up staining reagents with great 

 difficulty. The secretion from these cells depends on a process of 

 swelling, which gradually extends downwards ; they are not confined 

 to secreting once only. The goblet-cells are independent structures, 



* Science, vii. (1886) p. 35. f Biol. Ceutralbl., v. (1885) pp. 499-502. 



