IGO PROGRESS OF MICROSCOPICAL SCIENCE. 



The origin of the nucleated cells I had not been able to ascertain — 

 that is, from what part of the Difflugia they come. That of the monad- 

 like bodies I knew to have come from the nucleus, which frequently 

 (under reproductive circumstances ?) breaks up into these bodies, and 

 therefore, in this case, was not present — had thus disappeared ; while 

 the amoeboid bodies without ciliimi seemed to be but a more advanced 

 state of the passive nucleated or ovi-like cells. 



Thus I inferred that the small monociliated bodies coming from 

 the nucleus were the male elements, and the larger nucleated cells 

 the female elements, which, meeting together in the body of the 

 parent, were, in their plastic state, thus brought together at the most 

 favourable moment for impregnation, ?'. e. for the blending of the two 

 elements. While the active amoeboid bodies tvithout cilium might have 

 been the product after impregnation, thus prepared for independent 

 existence when the parent might choose to throw them off, or might 

 become effete and thus by dissolution allow them to escape into the 

 water. 



I have much more that I could state to you on the subject, but 

 neither my leisure nor your patience, I fear, admits of the extension. 

 Sufficient however has been written to show you the amount of interest 

 I still take in these matters, and thus to prove to you how acceptable 

 was the copy of your paper. 



I am, my dear Sir, 



Yours very truly, 



Henry Cakter. 



PEOGEESS OF MICEOSCOPICAL SCIENCE. 



The Spectroscope in Microscopy. — Those who are interested in this 

 peculiar department of the microscope will be interested in reading a 

 very useful paper on the subject in Max Schultze's ' Archiv,'* pub- 

 lished in May last. Messrs. Sorby and Browning have their earlier 

 labours very fully recognized by the author, Herr S. Valentin. 



The Anatomy of the Hetina. — This is a subject which is taken up 

 by Herr Max Schultze, who has a new paper on the subject in the May 

 number of his ' Archiv.' It is illustrated by a very admirable plate, 

 and is of considerable length. This wurk also contains a paper on 

 micro-photography. It is illustrated by a couple of photographs, one 

 of blood, the other of bone, which however do not reflect very much 

 credit on the photographer, being in no way to be compared with Col. 

 Woodward's efforts. 



The Embryology of Scorpions. — One of the finest memoirs that 

 have for years been published on this subject is the splendid essay 



* 7 Band, 3 Heft. 



