336 SPECIAL HISTOLOGY. 



Blood-corpuscles of other animals. — The non-nucleated blood- 

 corpuscles of the Mammalia do not differ in form from those 

 of Man, except that in the Camel and Llama (Auchenia Paco, 

 A. Glama, A. Vicugna) they are oval, and 00038'" long ; they 

 are mostly smaller than in Man, as in the Dog, 0-0031'", Rab- 

 bit, Rat, 0-0028'", Swine, 0-0027'", .Horse and Ox, 00025'", 

 Cat, 0-0024'", Sheep, 0-0022", the smallest (0-00094'") in the 

 Musk Deer; seldom larger (0-005'") as in the Elephant. All 

 the lower Yertebrata have, almost without exception, oval, 

 nucleated blood-corpuscles, of the shape of a melon-seed. Those 

 of Birds are from 0004"' to 0*008'" long, and contain roundish 

 nuclei ; those of the Amphibia measure between 0-008 — 0025"' 

 in length, have round and oval nuclei, and are largest in the 

 naked Amphibia (Frog, 0-011 — 0013'" long, 0-007— 0008"' 

 broad; Proteus, 0-025'" long, 0-016'" broad; Salamander, 0-02"' 

 long) ; those of Fishes, lastly, are mostly 0-005 — 0*007'" long, 

 except that in the Plagiostomes they measure 001 — 0*015"'; in 

 the Lepidosiren they are 0*020'" long, and 0012'" broad. In 

 Myxine and Petromyzon they are 0-005'" in diameter, round, and 

 slightly biconcave. In Amphioxus the blood-corpuscles are ab- 

 sent. 1 The blood-corpuscles of the Invertebrata 

 Fig. 293. resemble the colourless cells of the blood in 



{ t, c the higher animals, and ar§ almost always un- 

 coloured. 



The following should here be also noticed 

 as extraordinary constituents of the blood : 1. 

 (\ A cells, enclosing blood-corpuscles, noticed by Ecker 



*&* and myself in the blood of the spleen and he- 



patic vessels, and elsewhere also in the blood (vid. 

 Mikroskop. Anat., TI, 3, p. 369. et seq.) 2. pigmented and colour- 

 less granule-cells, observed by myself, Ecker, Meckel, Virchow, 

 and Funke, particularly in cases of intermittent fever and diseases 

 of the spleen (1. c.) 3. pale, fine -granular, roundish aggregations, 

 in the blood of the splenic vein (Funke). 4. peculiar con- 

 centric bodies, three to four times larger than the white blood- 

 cells, similar to those of the thymus (vid. Henle, l Zeitsch. f. 

 rat. Pathol./ Bd. VII, p. 44), found by Hassall in fibrinous clots 



Fig. 293. 1, blood-cells of the Frog: a, viewed on the side; b, on the edge; c, 

 rendered colourless by water. 2, Blood-cells of the Pigeon : a, viewed on the side ; 

 b, on the edge. 



' [rid. Note, p. 330.— Eds.] 



a i 



