86 Dr. Beale, on the Ovarian Ova of the Stickleback. 
facts in connection with the structure of the germinal vesicle 
and the development of the ovarian ova learnt by the process 
of investigation I have pursued, but content myself with re- 
ferring to the drawings in Plate VII, and the descriptions 
underneath them. 
In conclusion, I will only observe that the ammonia does 
not dissolve either the germinal vesicle or its contents ; and 
I fear that when my friend sees the drawings he will be in- 
clined to reply that, so far from exhibiting solvent properties, 
the fluid has precipitated particles from the contents of the 
germinal vesicle, and has actually formed things which do 
not exist in the natural state. I will not, however, now 
discuss this matter. 
The best results are obtained by diluting the carmine fluid I 
have recommended with a little water and spirit of wine. I 
have already stated that, for special inquiries, the staining 
fluids will be improved by slight modifications, which will sug- 
gest themselves to any observer after a few careful experi- 
ments. So, also, some things are stained most easily at ordinary 
temperatures, others -at a temperature of 100°; but it would 
be tedious beyond measure to give detailed directions for 
each individual object. If the experimenter considers the 
principles upon which the success of the process depends, 1 
think he will find little difficulty in carrying it out. Like 
many other operations, practice is required before the best 
results are obtained, and most who anticipate complete suc- 
cess upon the first trial will, I fear, be disappointed in this 
as in most other scientific investigations. 
