ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
511 
it is possible that the retina of Vertebrates has been evolved by the 
coalescence of very small groups of sense cells that were at one time 
separate and simple sense organs. 
Peculiar Mitosis in young Oocytes of Salamander.* — Dr. F. Meves 
describes peculiar mitotic processes in the oocytes of Salamandra 
maculosa , observed at the stage when aquatic life is abandoned. As 
the larvae were all born in captivity, abnormal conditions may have had 
to do with the peculiarities. 
The oogonia show a nucleus with few chromatin fragments and a 
very delicate, but dense linin-framework. As they become ova, a fine 
narrow-meshed chromatin network appears, which afterwards changes 
into a coarser coil. A longitudinal cleavage of the chromosomes was 
observed. Young oocytes, in the stage with a narrow-meshed chromatin 
network, exhibited a mitotic process which ends in degeneration. The 
chromatin network becomes a fine coil ; a longitudinal splitting of 
chromosomes follows ; the double rods (twelve) separate, shorten, thicken, 
may anastomose, and behave quite abnormally ; the nuclear membrane 
disappears ; only a single central point of radiating filaments is usually 
apparent ; the chromatin elements, occupying a peripheral position, are 
halved transversely, and each group consists of four spherules ; the 
elements are bent towards the centre of the radiation, and degeneration 
sets in. 
Probably the phenomena, which are merely outlined in the above 
summary, represent the introductory phases of premature and abnormal 
directive-divisions. 
Retrogression of the Karyokinetic Spindle. | — Mr. A. Bolles Lee 
observes that in the spermatogonia and spermatocytes of the snail 
the karyokinetic spindle in the “ regression ” is often a compact body 
uniting the daughter-cells. This is the “ problematic body ” of Platner. 
The bridges may persist for several successive generations, forming 
a chain — the Zellkoppel, or intercellular ligament of Zimmermann. 
It is admitted that the retrogression may take other forms, but the 
caution is submitted that the retrogressive stages of the spindle may 
be mistaken for attractive spheres, centrosomes, and even intercellular 
parasites. 
Eosinophilous Cells of some Fishes.f — M. J. Siawcillo has examined 
the eosinophilous cells of three species of fish, the gudgeon ( Gobio 
fluviatilis ), the Russian loach ( Gobitis fossilis) and the skate ( Baia 
denticulata). The blood was fixed by dry heat or alcohol and ether, 
and then stained with the triple Ehrlich solution, or with eosin (aqueous) 
and aqueous methylen-blue solutions. The leucocytes with large 
granulations were not observed in the loach. In the skate they were 
numerous and in this fish were observed other cells, the protoplasm of 
which was filled with fine needle-like crystals also staining with eosin. 
The eosinophilous granulations of the skate responded to all the micro- 
chemical tests for albumen. The fact that the skate is devoid of bone 
marrow and is possessed of numerous large eosinophilous cells seems to 
* Anat. Anzeig., x. (1895) pp. 635-45 (5 figs.). 
t La Cellule, xi. (1895) pp. 29-51 (1 pi.). 
x Ann. Inst. Pasteur, ix. (1895) pp. 289-300 (l colrd. pi.). 
