1890-91.] AMPHIBIA BLOOD STUDIES. 221 



STUDIES ON THE BLOOD OF AMPHIBIA. 



By A. B. MACy\LLUM, M.B., Ph.D. 



Lecturer on Physiology, University of Torojito. 



(Read lyth January^ i8gi.) 

 CONTENTS. 



Section i. The Origin of Haemoglobin. 



a. Methods of Study. 



b. Structure of the Blood Corpuscles. 



c. The Origin of the Haemoglobin in the Red Discs. 

 Section 2. The Fusiform Corpuscles. 



Section 3. The Origin of the Haematoblasts. 

 Section 4. Conclusions. 

 Section 5. Appendix. 



I. The Origin of H.'Emoglobin.* 



In the following pages are given the results of studies commenced 

 five years ago and continued with short intermissions till last summer. 

 The length of time taken up in this work was necessarily great because of 

 the lack of previous studies in the same line and because of the want of 

 definite and exact knowledge on the subject of the micro-chemical 

 reactions of haemoglobin. The difficulty of detecting, by chemical or 

 microscopical methods, any antecedents of haemoglobin appeared so 

 formidable that, at one time early in the work, I was on the point of 

 abandoning the line of investigation altogether. 



I have used for this investigation our Lake Lizard, Nectiirus lateralis, 

 and the larvae of Amblysioma piinctatum which are readily obtainable in 

 large numbers in the immediate neighborhood of Toronto in April and 

 May. The advantages which the tissues and structures in the Necturus 

 present for cytological work far outweigh those which a comparative 

 study of the blood in a larger number of Amphibian forms would have 

 and there is, therefore, a justification for narrowing the investigation to 

 the two named forms. 



* The subject matter of this paper was included in a thesis presented for the degree of 

 Doctor of Philosophy in the Johns Hopkins University, in April, 1888. 



