1872.] Mr. E. Ray Laiikester on Hcemoglobin. 79 



of abundant Haemoglobin in its vascular fluid may be supposed to be one 

 of the chief properties which enables the oligochaet Annelid Tubifex to 

 hold its ground in the foul, and therefore much deoxygenated, water of 

 the Thames at London. 



The known chemical properties of Haemoglobin furnish a more com- 

 plete explanation of its peculiar distribution in tissues. That it should 

 occur in a circulating fluid, which is the medium of respiration, is 

 obviously related to those properties. Its occurrence in the voluntary 

 muscles of the most active of Vertebrata, and in the most active muscles 

 of some others (as in the case of the dorsal-fin muscles of Hippocampus), 

 is equally so ; so also its occurrence in the most powerfully acting part 

 of the intestinal muscles, those of the rectum, and in the only rapidly and 

 constantly acting muscles of the Gasteropods, namely those used in 

 biting and rasping. 



To connect its occurrence in the nervous chain of Aphrodite aculeata 

 with its properties is more difficult, since we have no knowledge that this 

 Annelid is remarkable for nervous energy. The large bulk of the animal 

 in proportion to the size of the nervous system, and the deficient respira- 

 tion, indicated by the very slightly developed vascular system and the 

 total absence of Haemoglobin from the fluids of the worm, may be a rea- 

 son for the endowment of the nervous centre which has to control such 

 a large and complicated organism with a special facility for appropriating 

 what little oxygen may come in its way. 



The complete absence of Haemoglobin from Leptocephalus is an example 

 of the submission of an auxiliary, but not an essential, structural attribute 

 to an all-powerful necessity — that of transparency. The absence of Haemo- 

 globin from the transparent Annelid Alciope may be similarly correlated. 



From what has been stated above as to the Haemoglobin-bearing cor- 

 puscles of Glycera, Solen, and the Yertebrata, it appears that when Hae- 

 moglobin is present in the blood in corpuscles, these corpuscles are of a 

 peculiar character, and are specially related to the presence of the Haemo- 

 globin. When that is absent, other things remaining the same (as with 

 the blood of Solen ensis and the perivisceral fluid of most Annelids), the 

 peculiar corpuscles are absent. Such things as colourless corpuscles, 

 representative of the Haemoglobin-bearing corpuscles, do, however, appear 

 to exist in the case of the fish Leptocephalus. In connexion with the 

 relation of the colourless corpuscles of vertebrate blood to the red cor- 

 puscles, and of the corpuscles of the vascular fluids of Invertebrata to 

 one another and to those of Vertebrates, these facts seem to be important : 

 the colourless corpuscles in one case are only comparable to the colour- 

 less in another ; the red corpuscles are something apart, which may or 

 may not be superadded*. 



* {Note. Dec. 24th, 1872.] — The two kinds of corpuscles may be definitely distin- 

 guished from one another as leucocytes and pneumocytes. 



VOL. XXI. Cr 



