ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 6] 
however, agrees with the Austrian author in the propriety of establishing 
for it a new genus. 
Coccoliths.* * * § — Mr. E. H. L. Schwarz comes to the conclusion that the 
discolith represents the adult stage of the coccolith, and is a separate 
organic individual, consisting of a phosphatic disc, which appears to be 
surrounded with protoplasm. He is inclined to think they should be 
removed from the Animal Kingdom, and put provisionally near Gloeo- 
capsa and Chroococcus , to which they are allied by their mode of 
reproduction. 
Encystation of Actinosphserium.f— Dr. A. Brauer describes the pro- 
cess of encystation in Actinosphserium Eichhorni, The animal draws in its 
pseudopodia and excretes a gelatinous envelope ; the vacuolar structure 
becomes less distinct ; yolk -like granules appear in the medullary layer ; 
flinty skeletal pieces are excreted all through and gradually displaced 
towards the periphery ; a large number of nuclei fuse together. Then 
the animal falls into as many portions — cysts of the first order — as there 
are nuclei. Each cyst excretes a gelatinous envelope. Then by division 
of cell and nuclei, cysts of the second order are formed, which, after 
division has ceased and the flinty envelopes are fully formed, become 
resting cysts. Each resting cyst has one large central nucleus, around 
this a zone of granules, then a cortical layer without granules, then the 
siliceous envelope. A gelatinous envelope surrounds two or four cysts, 
and a second gelatinous envelope surrounds all. Dr. Brauer does not 
think that the fusion of nuclei has anything to do with “ fertilization ” ; 
the breaking up into fragments may be associated with the large size of 
this Protozoon, for it is too large to encyst in toto ; multiplication is 
wholly due to division of the cysts of the second order. 
Division of Amoeba.J — Dr. F. Schaudinn has observed the amitosis 
of Amoeba crystalligera Gruber, thus confirming Prof. F. E. Schulze’s 
observation of A. polypodia M. Schultze. The resting nucleus has a 
round or oval central body (or nucleolus), which stains slightly, but has 
an alveolar structure like that of the outer nucleus. This central body 
appears to play an important part in the direct division. The nucleus 
elongates, becomes slightly constricted, then dumbbell-shaped, and 
divides. As the daughter nuclei pass back into the resting stage the 
cell-substance divides. On a living animal the nuclear division occupied 
scarcely a minute ; the division of the cell followed in two minutes or not 
for hours. 
Movements of Gregarines.§ — Dr. W. Schewiakoff has studied Clep- 
sidrina munieri and other species of this genus, and finds that the move- 
ment is caused by the excretion of gelatinous threads, which emerge by 
fine longitudinal clefts in the cuticle from a layer between the cuticle and 
the ectoplasm. Why the excretion should form threads he has not dis- 
covered. When the substance of the gelatinous layer is exhausted, the 
Gregarine must rest until a new supply accumulates. 
* Ann. and Mag. Nat. Hist., xiv. (1894) pp. 341-6 (27 figs.), 
t Zeitschr. f. wiss. Zool., lviii. (1894) pp. 189-221 (2 pis.), 
t SB. Ak. Preuss., 1894, pp. 1029-36 (5 fig 9 .). 
§ Zeitschr. f. wiss. Zool., lviii. (1894) pp. 340-54 (2 pis.). 
