136 NUNNELEY, ON THE CRYSTALLINE LENS. 
following morning. The observations made in Lapland, at a 
time when the daylight there lasted during the whole night, 
the beginning and end of the division were observed to take 
place at almost the same hours as in the observations made at 
Breslau in the spring, when the day and night were almost of 
equal length. Sometimes the division ceases after the forma- 
tion of only four primordial cells (fig. 21). On one occasion 
the authors observed a family with only three cells, one only 
of the two halves first formed having undergone a second 
division. In Lapland a family with sixteen cells was once 
observed. 
The authors then proceed to discuss the nature of the 
resting-cells in Stephanosphera and Chlamydococcus, and 
come to the conclusion that they are not spores; 7.e., that 
they are not of the same nature as the red cells of Gidogo- 
nium, Bulbochete, Draparnaldia, Chzetophora, Spheeroplea, 
Volvox, &c. 
They come to this conclusion upon two grounds: Ist, that 
the resting-cells in question continue to grow after becoming 
quiescent ; and, secondly, that it is probable (although not 
yet proved) that the resting-cells increase by self-division, 
thus producing new generations of resting-cells. These two 
characteristics the authors consider inconsistent with the 
idea of a spore. 
In conclusion the authors notice the formation of mi- 
erogonidia in Stephanosphzera, which takes place by the 
division of the primordial cells into numberless small por- 
tions. Fig. 26 shows a Stephanosphera, in which all the | 
eight primordial cells have formed microgonidia; the indi- 
vidual microgonidia (fig. 27 a, 6, c) become free by the dis- 
integration of these eight groups into their constituent 
portions. The authors think it not improbable that th 
microgonidia exercise an impregnative influence in spore- 
formation, but admit that there is no evidence to prove it. 
On the Form, Density, and Strucruret of the CRYSTALLINE 
Lens. By Tuomas Nunne ry, F.R.C.S.E., Lecturer on 
Surgery in the Leeds School of Medicine, Surgeon to the 
Leeds General Eye and Har Infirmary. 
Tue Lens, as its name implies, is the most important por- 
tion of the dioptical ocular apparatus. It is at the same time 
the most perfect of its kind in the world. It has hitherto 
(and probably will continue so to do,) defied the efforts of 
