OF THE BLOOD. 225 



after the proper quantity of water has been added, the flat ve- 

 sicles disappear, leaving their middle particles, which seem to 

 be globular and very small (cv). 



That these red vesicles of the blood, although flat, are not 

 perforated, is evident, likewise, from a curious appearance which 

 I have repeatedly observed in blood that has been kept three 

 days in the summer season, until it was beginning to putrefy ; 

 the vesicles of this blood being diluted with serum, and examined 

 with a lens i of an inch focus (but more particularly when 

 examined with M. de la Torre's glass, which by his computation 

 magnifies the diameter 1280 times), were found to have become 

 spherical, the diameter of these spheres were less than their 

 largest diameter when flat, and their external surface was cor- 

 rugated in such a manner as to make them appear like small 

 mulberries (cvi). 



I have seen the same appearance on mixing serum (that had 

 been kept three days in a warm place, and smelt putrid) with 

 fresh-drawn human blood; the vesicle assumed this globular 

 and mulberry-like appearance. In these experiments on human 



(cv.) In birds, with some exceptions, the nucleus of the blood- 

 corpuscle, when exposed by acetic acid, is a longer oval than the un- 

 changed envelope. The nucleus of the corpuscle of oviparous verte- 

 brata is insoluble in water or in acetic acid ; but when soaked in 

 water the nucleus swells into a globular form, so as closely to re- 

 semble a lymph globule,* and retains that appearance for many days, 

 as shown in the ''London and Edinburgh Philosophical Magazine' 

 for August, 1842, p. 109, fig. 2. Hence the globular appearance which 

 Hewson notices in the nucleus, was probably caused by the action of 

 water. 



(cvi.) Granulated, angular, and jagged .forms are very common in 

 the perfectly fresh blood of mammalia, especially in young animals. 

 I have commonly seen such altered corpuscles in the blood of puppies 

 and kittens just killed. These corpuscles are rather smaller than the un- 

 changed discs, and either irregular in shape, granulated throughout and 

 nearly globular, or slightly flattened and indented, often with minute 

 molecules attached. See Appendix to Gerber's 'Anatomy,' pp. 9, 10, 

 23, 24, 93, 99, fig. 268 ; where references are given to the observa- 

 tions of Dr. Barry on the spontaneous division of the blood-discs ; of 

 Mr. John Queckett on the parent discs throwing from their interior small 

 globular particles ; and of Professor Valentin on the minute granules so 

 arranging themselves as to form the envelope of the blood-corpuscle. 



a See Note cxxn. 



15 



