( 171 ) 



PROGRESS OF MICROSCOPICAL SCIENCE. 



The Distribution of Haemoglobin in the Animal Kingdom. — One of 

 the, if not the very best papers which have been published on this 

 subject is that by Mr. E. Ray Lankester, B.A., which appears in a 

 late number of the ' Proceedings of the Eoyal Society.' * It is illus- 

 trated by a most carefully drawn plate, which, however, we cannot 

 reproduce. The following, which is a considerable portion of this the 

 most exhaustive essay that has been published on the subject, is most 

 of what this observer has stated : — • 



" The facts ascertained as to the distribution of Haemoglobin may 

 now be summarized as follows: — 

 "1. In special corpuscles. 



a. In the blood of all vertebrates, excepting Leptocephalus and 

 Amphioxus (?). 



b. In the perivisceral fluid of some species of the Vermian 

 genera Ghjcera, Capitella, Phoronis. 



c. In the blood of the Lamellibranchiate Mollusk Solen legumen. 

 " 2. Diffused in a vascular or ambient liquid. 



a. In the peculiar vascular system of the Cluetopodous Anne- 

 lids very generally, but with apparently arbitrary exceptions. 



b. In the vascular system (which represents a reduced peri- 

 visceral cavity) of certain leeches, but not of all. (Nephelis, 

 Hirudo.) 



c. In the vascular system of certain Turbellarians as an 

 exception (Polia). 



d. In a special vascular system (distinct from the general 

 blood-system) of a marine parasitic Crustacean (undescribed) 

 observed by Professor Edouard van Beneden. 



e. In the general blood-system of the larva of the Dipterous 

 insect Cheironomus. 



f. In the general blood-system of the pulmonate mollusk Pla- 

 norbis. 



g. In the general blood-system of the Crustaceans Daphnia 

 and CJieirocephalus. 



" 3. Diffused in the substance of muscular tissue. 



a. In the voluntary muscles generally of Mammalia, and 

 probably of birds, and in some muscles of reptiles. 



b. In the muscles of the dorsal fin of the fish Hippocampus, 

 being generally absent from the voluntary muscular tissue of fish. 



c. In the muscular tissue of the heart of Vertebrata generally. 



d. In the unstriped muscular tissue of the rectum of man, 

 being absent from the unstriped muscular tissue of the alimentary 

 canal generally. 



e. In the muscles of the pharynx and odontophor of Gasteropo- 

 dous Mollusks (observed in Lymnmus, Paludina, Littorina, Patella, 



* Vol. xxi., No. 140. 

 VOL. IX. 



