EXPLANATION OF PLATE I. 



The Figures in this Plate represent the Cells floating in the various animal fluids ; and 

 they are all, with the exception of Figs. 4 and 5, copied from the representations given 

 by M. Donng in his "Atlas de 1' Anatomic Microscopique." These representations are 

 transcripts of Daguerreotype pictures, obtained from the objects, by a solar microscope, 

 with a magnifying power of 400 diameters. 



Fig. 1. Red Corpuscles of Human Blood, viewed by their flattened surfaces ($ 215). 



Fig. 2. Red Corpuscles of Human Blood, adherent by their flattened surfaces, so as to 

 form rolls ; at a, the entire surfaces are adherent ; at Z>, their surfaces adhere 

 only in part. 



Fig. 3. Red Corpuscles of Human Blood, exhibiting the granulated appearance which 

 they frequently present, a short time after being withdrawn from the vessels. 



Fig. 4. Colourless Corpuscles of Human Blood ( 214). 



Fig. 5. The same, enlarged by imbibition of water. 



Fig. 6. Red Corpuscles of Frog's Blood ( 215). 



Fig. 7. The same, treated with dilute acetic acid ; the first effect of which is to render 

 the nucleus more distinct, as at b ; after which the outer vesicle becomes 

 more transparent, and its solution commences, as at a. 



Fig. 8. The same, treated with water ; at a is seen a corpuscle nearly unaltered, except 

 in having the nucleus more sharply denned ; at 6, others which have become 

 more spherical, under the more prolonged action of water ; at c, the nucleus 

 is quitting the centre, and approaching the circumference, of the disk ; at d 

 it is almost freeing itself from the envelope ; and at e it has completely 



Fig. 9. Globules of Mucus, newly secreted ( 237). 



Fig. 10. The same, acted on by acetic acid. 



Fig. 11. Globules of Pus, from a phlegmonous abscess ($ 637). 



Fig. 12. The same, acted on by acetic acid. 



