THE CAKMINE PROCESS. 65 



with this same carmine solution has been said to de- 

 prive the test of all value. To this Dr. Beale replies 

 that mere steeping of tissues and other formed matters 

 in the solution till they are soaked through with the 

 colouring matter, will certainly tint all kinds of formed 

 matters ; but the staining he means is essentially dif- 

 ferent from that mere tinting, and by observing proper 

 precautions it can easily be secured. 



Dr. Ransome, in his paper on the " Ovum of Osseous Fishes " 

 (" Phil. Trans.," 1867), reports unfavourably of the process as a 

 means of distinction of the living and dead, for he says the 

 yelk sac and some other kinds of " formed material " took the 

 colour more quickly than the protoplasm. 



And again, in his paper on the " Ovarian Ovum of the Gas- 

 terosteus Leiurus" ("Quart. Mic. J.," 1867, p. 1), he repeats his 

 objection, and states that the ammonia in Beale's carmine fluid 

 " rapidly dissolves the germinal vesicle and its contents," and 

 that " the granular formative yelk takes the dye with greater 

 difficulty than the yelk sac does, except in very young ova, and 

 the inner sac a true germinal matter does not take any 

 stain ; so that I cannot accept the staining of certain parts of 

 a structure as satisfactory evidence of the distribution of ger- 

 minal matter in the tissue." In reply to this, Dr. Beale states, 

 at p. 85 of same volume, that the ammonia does not dissolve 

 the germinal vesicle or its contents, although it may precipitate 

 some particles from the contents, and somewhat alter its ap- 

 pearance ; and that in the staining Dr. Ransome has probably 

 failed from not observing certain precautions and modifications 

 necessary in practice for different objects. In proof of this, he 

 gives the plate of the ova of the stickleback perfectly stained 

 according to Ms method. This plate is also to be seen at 

 p. 306 of " The Microscope," 4th edition. I would also add, 

 that in the above memoir in the " Phil. Trans.," Dr. Ransome, 

 after saying that the yelk sac took the carmine freely, goes on 

 thus : " The dyeing is independent of any acid reaction of the 

 substance dyed, as macerated yelk sacs which had been alkaline 



5 



