480 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Having made a selection, a drop of the concentrated solution of nitrate 

 of rosanilin was deposited on the glass and allowed to remain for a 

 few moments, and then washed off with a fine jet of distilled water. 

 The red, pale and colourless corpuscles, with their ramifications and 

 the most delicate fibrils of fibrine, then become visible under a high 

 power. The preparations may be mounted dry, and will keep for a 

 great length of time. If the process be performed as rapidly as the 

 dexterity gained by an oft-repeated experiment will allow, it will be 

 observed that the circular appearance of the corpuscles is perfectly 

 preserved, and that every shade of colour may be found, from the 

 normal red corpuscles down to the colourless Norris corpuscle, which 

 only takes the faintest tint of pink. If, however, the glass surfaces 

 be allowed to remain in contact for a moment, the colourless cor- 

 puscles are found to have lost their globular form, and to have become 

 pyriform or elongated. On leaving the glass surfaces still longer in 

 contact, these pale corpuscles are observed to undergo a remarkable 

 change. They send out long processes or tails, which bifurcate and 

 divaricate in every direction. On allowing a still longer interval to 

 elapse, so that it is more than probable that coagulation would occur in 

 a film of blood lying between two glass surfaces, and on separating 

 these surfaces, perfect specimens of fibrine may be obtained after 

 staining. On now searching the field, the pale corpuscles, which 

 could formerly almost always be discovered, are nowhere to be found, 

 and the conclusion is forced upon one that the branching corpuscles 

 have developed or broken down in fibrinous threads. Small granules 

 are, however, found from which threads of fibrine appear to spring. 

 These granules are described in Eanvier's 'Traite Technique 

 d'Histologie ' as the centres of fibrine formation. They appear to the 

 author to be all that is left of the pale corpuscles, whose intermediate 

 transformations have not before been recognized, but may perhaps be 

 identified with the appearances and changes described. Amongst 

 other figures, one is given showing the departure of the fibrils of 

 fibrine from the pale corpuscles. 



Hew Blood-corpuscle.*— According to G. Bizzozero, if the circu- 

 lating blood in the small vessels of the mesentery of chloralized 

 rabbits or guinea-pigs is observed under a high power, there will be 

 seen, besides the ordinary red and white cells, a third form of cor- 

 puscle which is colourless, round or oval, and from one-half to one- 

 third the size of the red corpuscle. He considers that they have 

 hitherto escaped the notice of observers (1) owing to their translucency 

 and want of colour ; (2) because they are less numerous than the 

 red, and less visible than the white corpuscles ; (3) owing to the great 

 difficulty of observing the circulating blood in the small vessels of 

 the warm-blooded animals. They can be seen also in freshly drawn 

 blood, for the most part aggregated around the white corpuscles, or 

 immediately under the cover-glass, to which they adhere. They 

 Boon become granular, and give rise to what is called the granule- 

 masses. Through appropriate reagents their form can be preserved. 



* Arch. Ital.de Biol., i. (1882) pp. 1-4 ; cf. ' The Microscope,* ii. (1 882) pp. 59-60. 



