428 Dr. John Mutter's Examination of [June 



diameter of the globules in men is four or five times greater 

 than the broad diameter, and in the frog eight or ten times 

 more extensive. Of the animals examined by Miiller, they 

 are smallest in men and mammalia, (among the latter the 

 goat possesses the most minute globules, according .to 

 Prevost and Dumas, a fact which is confirmed by Miiller,) 

 a little smaller in the calf, largest in the naked amphibia, 

 and inferior in size in birds, fish, and scaly amphibia. In 

 man their broad diameter was found to be 0*000245 — 

 0-000373 English inch. The globules of the blood in birds 

 are half as large as those of the frog, and of the latter 

 animal the globules are many times larger than in man. 



In the centre of the globules a spot may be detected, 

 round or elliptical, according to their form, which by 

 reflected light appears clear, and by transmitted light, 

 dark. Dr. Young considered this a cavity. When the 

 globules are held obliquely, so that part of one side is seen 

 and part of the upper edge, a dark semi-circle is formed by 

 the upper edge, the interior surface of which is convex and 

 the other concave. According to Miiller the globules of 

 the blood in the frog and lizard contain a nucleus, which 

 differs in chemical composition from the external substance 

 surrounding it. The same nucleus he detected in fishes 

 and birds, and in man he observed a very small round 

 substance, yellower and brighter than the transparent 

 matter which surrounded it. When the globules are placed 

 in acetic acid under the microscope, the exterior coat is 

 observed to be dissolved, leaving the nucleus in an isolated 

 state, which in the human blood it is very difficult to see, 

 but in the blood of the frog is very distinct. In the blood 

 of the frog a smaller kind of globules occur, which are 

 completely round, not flattened, and are much more minute 

 than the elliptical globules. 



Miiller conceives that the nuclei of the elliptical globules 

 may consist of the lymph and chyle globules, an opinion 

 which seems to be strengthened by the circumstance that the 

 chyle globules are completely insoluble in water, but that 

 the globules of the blood are soluble as far as the nuclei, 

 which are insoluble. As long as they are contained in the 

 serum their colouring matter is insoluble, but when they 

 come in contact with water the colouring matter is dissolved. 



