482 Mr. Gulliver's Contributions to the 



servable to the same degree in the pale globules of the blood of 

 these two classes. The account of the chemical characters of 

 the lymph-globules of mammalia, as given in the Appendix to 

 Gerber's Anatomy, is generally applicable to the corresponding 

 globules of birds. Professor Wagner observes, that the che- 

 mical properties of the pale globules of the blood and the nuclei 

 of the blood-discs of birds and reptiles are identical. This 

 appears to be true in most respects ; but in certain experiments 

 the two kinds of particles seem to me to be differently aifected 

 under precisely the same treatment. Thus the nucleus of the 

 blood-corpuscle is not so prone to change in drying as the 

 lymph -globule. The former, whether exposed in recent 

 blood by acids, or in dry blood by the moisture of the 

 breath, may be quickly dried, and the form of the nucleus 

 thus completely preserved, on the slip of glass used to make 

 the observation ; while the lymph-globule after similar treat- 

 ment, and even if dried without any addition, becomes either 

 faint, tumid, or misshapen. Certain saline solutions too, which, 

 in a few hours, either injure the shape of the lymph-globules 

 or render them almost invisible, do not act so remarkably on 

 the nuclei of the blood-discs. 



The pale globules noticed in this paper are those well-known 

 white and slightly granular corpuscles which are generally 

 seen at once very plainly in the blood, as they appear, under 

 certain adjustments of the object-glass, with a distinct and 

 dark circumference. But there are other pale particles in 

 the blood. Some of these are isolated, and agree in all re- 

 spects with the globules of the lymphatic juice, being smaller, 

 often rather fainter and with a less definite contour than the 

 pale globules first mentioned. In the blood after death there 

 is also frequently observable small shapeless white fragments 

 consisting of circular or oval granules hardly as large, seldom 

 larger, than the globules of the lymphatic fluid ; and minute 

 oil-like particles are often seen in the fragments. In birds 

 this granular matter often exactly resembles in structure the 

 colourless fibrine, obtained from their blood by washing it in 

 a linen bag, and the granules are frequently just like the nu- 

 clei of the blood-discs. The white granular matter is often 

 abundant when the pale globules are either difficult to be 

 found or entirely absent. 



The engraving may be considered as showing the relative 

 size of the pale globules of the blood and those of the juice 

 of the lymphatic glands in birds generally. The following 

 measurements of the lymph-globules are expressed in frac- 

 tions of an English inch ; the common sizes are first noted, 

 then a space is left, after which the measurements of the small 



