388 PROFESSOR ARTHUR BOETTCHER. 



apparently quite homogeneous. The concentrated alcoholic 

 solution of corrosive sublimate is alone able to reveal in the 

 blood-corpuscles of the camel the structural relations which I 

 had already become acquainted with in the human blood-cor- 

 puscles by the same metliod. 



III. The Red Blood-corpuscles of the Frog. 



A^fter I had proved in mammalian blood-corpuscles the great 

 advantages which are afforded by the method described, I could 

 not refrain from applying the same method to those blood-cor- 

 puscles which have hitherto alone been regarded as nucleated. 

 I have, however, not yet been able to examine in this respect all 

 classes of animals with distinctly nucleated elliptical blood- 

 corpuscles. 



Whilst reserving to myself farther communications in regard 

 to those of birds and fish, I shall at present only make some 

 statements with regard to the appearances which the blood- 

 corpuscles of the frog present when they have been treated with 

 an alcoholic solution of corrosive sublimate. I can be the more 

 concise in my remarks as the interpretation of the structural 

 relations meets with much fewer difficulties in regard to prevailing 

 notions on the subject. The drawings which 1 have added will 

 also materially assist in understanding them. 



That a granular protoplasm is collected round the nucleus of 

 the frog^s blood-corpuscle, and that filaments radiating outwards 

 from it, can be demonstrated in many blood-corpuscles, is by no 

 means generally admitted. It may even be asserted that with 

 the exception of the few observers who have devoted special 

 attention to this subject, no one has taken notice of the obser- 

 vations referring to it, which are, it is true, still incomplete. The 

 doctrine of '^Stroma" has also hindered the advance of our 

 knowledge of the structure of the blood-corpuscles. As far as I 

 know, only Hensen, myself, and KoUmann have investigated the 

 subject with any minuteness. Hensen first reported on the 

 appearances obtained by crushing fresh blood-corpuscles of the 

 frog. I then .confirmed his statements, and described further 

 the peculiar forms which a five per cent, solution of tannin 

 produces in the blood-corpuscles of the salamander. From these 

 observations it was inferred that around the nucleus of the 

 amphibian blood-corpuscles a mass of protoplasm is collectep 

 which radiates in the form of filaments into the homogeneous rep 

 substance. I laid especial stress on the fact that the blood- 

 corpuscles are not aL similar, but that there are many in which 

 the nucleus appears surmounted with only the colourless granular 

 matter, and again, others in which the latter cannot be demon- 

 strated at all. I feel obliged to make these preliminary remarks 



