294 M. M. Mercanr 
NERESHEIMER (1906, 1907) saw both microgametes and macro- 
gametes and saw them in copulation (Compare his Fig. B, on p. 26. 
One of his drawings from this figure is reproduced here in Text 
Fig. XI), but he failed to recognise this as copulation, interpreting 
it as abnormal budding. The forms which he describes as isogametes 
seem from his figures to have been microgamete mother-cells. He 
once saw two of these come together by their anterior ends and 
gradually fuse, closing together like the blades of a pair of shears. 
The nuclear phenomena in this case were not followed. This he 
took as showing the presence of isogamous copulation. Doubtless it 
was abnormal. In one instance I have found 
in an acetic carmine preparation two short- 
tailed forms of O. caudata, apparently micro- 
gamete mother-cells, attached, the tail of one 
being united to the side of the other (Fig. 
276, Pl. XXVII). This instance, with the 
Text Fig. XI. One of single instance which NERESHEIMER describes, 
NeresHemmer’s figures of seems to indicate that very rarely micro- 
“abnormal division in the gamete mother-cells of the same size may 
formation of the gametes ; : : ; ; 5 
sO. dimidiaia”. "Thie wag) Unite: I have in one instance in O. intesti- 
probably the attempted co- “als seen a microgamete attached by the 
pulation of three micro- whole anterior half of the body to a macro- 
gametes with one macro- oamete, the tail of the microgamete, being 
epieher: free (Fig. 181, Pl. XXIII). Neither the 
previous nor the subsequent stages of this copulation were seen. 
It was of course abnormal in the sense of being a departure from 
the regular method of copulation, but it may not have been patho- 
logic. It is similar to the instance that NrRESHErMER describes 
in that the male was not attached by its tail as in every other . 
of the several hundred instances of copulation I have seen. 
Chromatin spherules in the gametes and zygotes. 
In the mature nuclei, after the formation and extrusion of the 
chromatin spheres, I have not observed the formation of chromatin 
spherules, nor have I seen their formation in the syncaria soon after 
copulation. I cannot say positively that there is an interval when 
they are not formed, but this seems to be the case. 
Nucleoli in the gametes and zygotes. 
I have failed to find nucleoli in the nuclei of the gametes and 
young zygotes. In older zygotes they are present. 
