848 BECORD OP CURRENT RESEARCHES RELATING TO 



were observed to be red ; these globules or microcytes were observed 

 on only one occasion, aud after their appearance the patient in whom 

 they were found, exhibited a considerable, though unfortunately only 

 temporary, improvement. 



Two hypotheses present themselves in exj^lanation of the phe- 

 nomena: either the microcytes owed their origin to the secondary 

 formation of a number of new red corpuscles, which would require 

 a certain time to attain the normal size, or they were due to 

 tJie breaking up of a number of red corpuscles. The former 

 hypothesis is supported by the explanation oifered by several histolo- 

 gists as to the presence of the small red corpuscles which measure 

 from 6 to 6 • 5 micromillimetres in diameter ; while the second, which 

 seems to be the more satisfactory, would be sujiported by the cachectic 

 state in which the patient was found jjrevious to their appearance, aud 

 by the a priori supposition that it is more natural to regard them as 

 fragments of corpuscles, which have only become spherical owing to 

 the action of the fluid blood. The authors point out that the best 

 way to solve the question is to apply the colorimetric test and to dis- 

 cover whether the amount of hfemoglobin is increased, in which case 

 the former hypothesis would be shown to be the correct one, or 

 whether the haimoglobin is not increased in quantity, in which case 

 the presumption would be in favour of the second, and they promise 

 to i>erform experiments in this directiom 



Terminal Nerve-plexus in the Cornea.*— M. Eanvier, in an intro- 

 duction to an account of some experiments on the function of this 

 plexus, points out that in the rabbit the largest nerves are the deejjest, 

 and the smallest the most superficial ; that they all divide and sub- 

 divide dichotomously ; that they take a course towards the surface, 

 where they unite to form a large plexus. 



The results of his experiments go to show that (1) The view 

 of Snellen, in which the presence of trophic nerves in the cornea 

 was denied, is correct, inasmuch as nutrition is still regularly 

 effected after all the nerves which supply this region, are cut ; 

 (2) The nerve-filaments pass very rapidly into the jjlexus and always 

 retain their physiological and anatomical individuality — in other 

 words they merely form a 'plexus and not a network ; (3) This 

 plexiform arrangement of the nerves of the cornea does not seem 

 to have any sjiccial physiological duty, but to be due to the necessity 

 of an ai'rangement which shall not disturb the homogeneous cha- 

 racter of the membrane; (4) The nerves have only a general 

 sensibility, and yet their presence is not absolutely necessary; it is 

 " une fonction de luxe," inasmuch as the insensitive cornea may be 

 well protected by the sensitive conjunctiva and eyelids. 



Harderian Gland of the Duck.t — Dr. Jules MacLeod in a paper 

 on the histology of this gland says that it is a compound tubular gland, 

 being made up of glandular tubules disposed in a verticillate manner 

 around common canals, so as to form secondary tubules. 



* 'Comptes Eendus,' Ixxxviii. (1879) p. 1087. 



t 'Bull. Acad. Roy. Sci. Belgique,' xlvii, (1879) p. 797. 



