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KECORD 



OF CURRENT RESEARCHES RELATING TO 



INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, &c., 

 including Embryology and Histology generally. 



ZOOLOGY. 



A. GENERAL, including Embryology and Histology 



of the Vertebrata. 



Nucleus in Blood-corpuscles. * — Upon reading some months ago 

 Buttcher's demonstration of a nucleus in the mammalian blood-cor- 

 puscle after bleaching by corrosive sublimate and alcohol, it occurred 

 to Dr. W. T. Belfield, of Chicago, that the asserted nucleus might 

 be artificial, due to coagulation of albumen and extraction of water by 

 the reagents used. It seemed that if bleaching alone were to be 

 accomplished the same results should follow bleaching by other 

 methods. 



With this idea he procured specimens of fresh blood from man, 

 the dog, rat, and turtle, exposed the corpuscles to the action of various 

 bleaching agents — chlorine, sulphurous acid, acetic acid, a freezing 

 temperature — then, when the colouring matter had been removed, he 

 immersed them in weak solutions of anilin and carmine, and mounted 

 them in distilled water. He was careful to produce as nearly as 

 possible identical effects upon all the specimens treated by each re- 

 agent, using the same solutions for the same periods upon them all. 

 By each method nuclei were clearly demonstrated in the turtle's 

 blood, but in no other specimen was there any differentiation of 

 colour. It is true that some mammalian corpuscles after prolonged 

 immersion in the colouring fluid showed staining, but that staining 

 was invariably uniform from centre to circumference, proving con- 

 clusively the absence of a nucleus so far as carmine staining can 

 prove anything. 



On these observations he bases a strong suspicion that the alcohol 

 and corrosive sublimate used are responsible for the appearance of 

 nuclei in corpuscles treated by Bottcher's method. This suspicion 

 receives support from recent discoveries as to the structure of nuclei. 

 In the July number of the ' Quarterly Journal of Microscopical 

 Science ' Dr. Klein relates a series of observations, as a result of 

 which he affirms the nucleus to consist of a fibrillar network, im- 

 bedded in which is a ground substance ; that this intranuclear 

 network is continuous with a similar intracellular network ; that 

 niicleoli are merely the thickenings and shrivellings of these fibrils. 

 The natural shrivelling effect of alcohol might readily produce a 

 pseudo-nucleus in a blood-corpuscle from condensation of this intra- 

 cellular network. 



* 'Am. Quart. Micr. Journ.,' i. (1879) p. 238. 



