102 



THE NATURALIST. 



album en, and forming that tliin membrane between the exterior shell-covering 

 and the nucleotic germ-mass or cicatricula. 



The blood corpuscles are of two kinds — ^red and white, the red being 

 the more numerous. In man, the red corpuscle varies in size from one four- 

 thousandth of an inch to one twenty-eight-hundreth of an inch. We are 

 indebted to Leuwenhoeck and Malpighi, whose researches were made soon 

 after the invention of the microscope, for the discovery of these corpuscular 

 bodies in the blood. 



The blood is the product of the elaboration of chyle ; and acquires all 

 its nutritive and life-giving qualities in respiration. By means of the arterial 

 vessels, it penetrates to all the organs, distributing nutrition to every organic 

 tissue. The colour, as well as the composition of the blood, varies in different 

 sections of the animal kingdom ; red in the Vertebrates and Annelides, it is 

 white and pellucid as water in Insects and Crustaceans ; bluish-white in 

 MoUusca, yellowish in Holothurians and some other Invertebrates. This 

 difference in colour arises from the corpuscles, which are red in some cases, 

 and in others white or straw-coloured, or bluish-white. The temperature of 

 the blood of various animals according to the researches of Eudolphi and 

 Tiedemann, is : — 









Fahr. 





Fahr. 



Great Titmouse 







111.25 



Squirrel 



105 



Swallow 







111.25 



Ox 



104 



Ducks and Geese 



.106 



to 



111 



Ape 



103 



Common Hen 



.102 



to 



109 



Dog ... 



101 



Eagles, Hawks, &c. .. 



.104 



to 



109 



Cat 



...98 to 103 



Pigeon 



.106 



to 



109 



Elephant 



99 



Gull 







100 



Horse ... 



98.24 



Bat 







106 



Man 



98 



The blood contains oxygen, nitrogen, and carbonic acid, and in consider- 

 j^ng the chemical constitution of the blood, it may, as we remarked before, be 

 regarded as consisting of two parts, — the liquor sanguinis, and the blood 

 corpuscles floating therein. The following tabular synopsis of the composi- 

 tion of these two parts is based on the analysis of Schmidt and Lehmann 

 and is a modification of that quoted in Miller's Elements of Chemistry^ Vol. 

 III. p. 689 :— 



Specific gravity of blood corpuscles 1.0885 



