724 mi. H. 15. FANTllAM ON [Mav 3, 



III. The Cells in the Normal Ulood of Birds, 



ESPECIALLY CJ ROUSE. 



The eloineiits pi'esent in the blood of normal grouse may be 

 gi'ouped {IS : 



(rt) Erytlu'ocytes. 

 (6) Leucocytes, 

 (c) Thrombocytes. 



The leucocytes are further subdivided, and may be grouped as 

 mononuclear, polymorphonuclear, and eosino[)hi]e leucocytes, and 

 lymjihocytes. Mast cells, which are markedly basophile, are also 

 present. Erythroblasts also may be encounteied. These forms 

 may now be considered separately. 



(a) Erythrocytes. — These are the most abundant elements in 

 the blood. The erj'throcytes or red blood corpuscles ai-e oval in 

 contour (PI. LXIII, tig. 1). Thej-^ possess a well-marked oval 

 luicleus, centrally placed. The erythrocytes of grouse are about 

 11"5-12 p. long by 7-7'5 fj. Ijroad. In fresh jireparations the 

 cytoplasm of the red cells of healthy grouse is practically homo- 

 geneous, or but vei-y faintly granidar. Stained })reparations gi\e 

 the same results. It is i-aie for large granules, chromatoid 

 granules, or vacuolations to be present in the red cells of healthy 

 birds. The nucleus stains deeply, and shows a well-mai-ked 

 chromatic meshwoi-k with small net-knots upon it at intervals. 



The red cells of various birds are much the same. There may 

 be slight differences in size and shape. In figs. 2 and 3 are 

 depicted stained specimens of the red cells of the pigeon and 

 fowl respecti^'ely, from which it will be seen that the erythro- 

 cytes of the pigeon are slightly narrower than those of the grouse 

 and fowl, and somewhat less rounded at the ends. 



The number of red cells of grouse varied from 3,600,000 to 

 5,800,000 per cubic millimetre, averaging 4.300,000 per c.mm. 

 These figures result from ])lood-counts of 50 biids. 



The nuniber of red cells is a})parently higher in cock grouse 

 {e. g., 4,400,000 per c.mm.) than in hen grouse (e. g., 3,800,000 per 

 c.mm.). 



(b) Lpiicocyirs,- The leucocytes of grouse are a stdiject of much 

 intrinsic dilHcultv, and it is im])o.*-sible to consider the grouju'ug 

 arrangemeiit given below as more thau jnovisional. The classi- 

 fication of the leucocytes of birds can be ])laced on a leally sound 

 ba.sls only when ddailcd knf)wledge of the develo])nunt of nil the 

 elements of the Idood of l)irds has l)een obtained In spite of 

 gooil woik by Diiiys. J )antschak()ii". and othei-s, such a complete 

 develojancntal investigation of the blood of birds is still wanting. 

 Owing bolh to the lack of time at uiy disposal and to the great 

 ttcarcitv of gnite fresh material, I am unable to attempt such 



