THE BLOOD-PLATES. 



arrest the locomotive movements, as well as the protrusion of pseudopodia, although the 

 vtes of different animals vary somewhat in their resistance to the action of drugs. 

 Qninine not only arrests the movements of the leucocytes when applied to them directly, but 

 when Injected into the circulation of a frog the leucocytes no longer pass through the walls of 

 the capillaries (Bin:). 



The ehvle contains leucocytes, which are more resistant than those of the blood, but less so 

 than those of the coagnlable transudations. The leucocytes of the lymphatic glands may also 

 be dissolved [Hautehenbaeh). 



Relation to Aniline Pigments. -Khrlich has observed a remarkable relation of the white 

 oorpoeeles to add (eosin, picric acid, aurautia), basic (dahlia, acetate of rosanilin), or neutral 

 (pi. rate of rosanilin) reactions. The smallest protoplasmic granules of the cells have different 

 enemies! affinities for these pigments. Thus Ehrlich distinguishes " eosinophile," "basophile," 

 and " nentrophile " granules within the cells Eosinophile granules occur in the leucocytes 

 which come from bone-marrow, the myelogenic leucocytes. The small leucocytes, i.e., those 

 about the si/e of a coloured blood-corpuscle or slightly larger, are formed in the lymphatic 

 glands, the lymphogenic. The large amoeboid multi-nucleated cells, which are found outside 

 the vessels in inflammations, exhibit a neutrophile reaction. Their origin is unknown, and 

 so is that of the large uni-nucleated cells, ami the large cells with constricted nuclei. The' 

 eosinophile corpuscles are considerably increased in leukaemia. The basophile granules occur 

 also in connective-tissue corpuscles, especially in the neighbourhood of epithelium ; they 

 are always greatly increased where chronic inflammation occurs. 



III. Blood-Plates. - Special attention lias recently been directed to a third 

 element of the blood, the " blood-plates " or " blood-tablets " of Bizzozero ; pale, 

 colourless, oval, round, or lenticular discs of variable size (mean, 3 //, ). In a 

 healthy man Fusari found 18,000 to 250,000 in 1 cubic millimetre of blood. These 

 blood-plates may be recognised in the circulating blood of the mesentery of a 



1 



\ 



3^ 



J; 



5 



V 4 



4 a 



* o 



Fig. 12. 



Blood-plates , ' ami then- derivatives. 1, a red blood-corpuscle on the flat ; 2, on the side ; 3, 



unchanged blood-plates ; 4, lymph-corpuscle, surrounded by blood-plates ; 5, altered bloodl 



plates ; 6 lynmh-crpusle with two heaps of fused blood-plates and threads of fibrin ; 7, 



SmSfa ^looci-plat-s ; 8, small group of partially dissolved blood-plates with fibrils 



chloralised guinea-pig and the wing of the bat. They are precipitated in enormous 

 numbers upon threads sus! en led in fresh shed blood. They may be obtained from 

 blood flowing directly from a blood-vessel, on mixing it with 1 per cent, solution of 

 osmic acid They rapidly change in shed blood (fig. 12, 5), disintegrating, forming 

 small particle* and ultimately dissolving. When several occur together they 

 rapidly unite, form small groups (7), and collect into finely granular masses. 

 Uie.se masses may be associated in coagulated blood with fibrils of fibrin (tig 12) 



[These blood-plates are best seen in the shed blood of the guinea-pig, especially if ft be 

 mixed with a solution of iodic sulphate (sp. gr. 1022) or f per cent. Nafcl tinged with methyl 

 vmlet. Buroxero regards then, as the agents which immediately induce coagulation and tSe 



