( 26 ) 

 PllOGRESS OF MICROSCOPICAL SCIENCE. 



27*6 Muscular Tissue of Corethra jylumicornis. — This is very fully 

 described in an article in a late number of Max Scliultze's ' Archiv,' * 

 by Herr G. E. Wagener. He enters upon the subject of its develop- 

 ment, and he points out many facts which show that it is in its 

 development not unlike the ordinary striated muscle of vertebrate 

 animals. A couple of excellent plates, done in the ' Archiv's ' best 

 style, accompany the paper. 



The Betelopment of the Ovum in Anodonta. — This is a subject 

 which is partly worked out by Herr W. Flemming, who is Professor 

 of Anatomy in Prague. He shows among other things the peculiar 

 form of the zoosperms and the mode in w^hich they enter through the 

 micropyle. This pajjer, which extends over more than thirty-five 

 pages, is illustrated by a good plate.f 



Has the so-called Microsimron Audounii any Existence ? — This 

 question is very well discussed in the ' Archives de Physiologic ' 

 (May, 1874), by M. Malassez, who, having debated the question very 

 fully, arrives at the conclusion that it is j)resent, but differs t ) some 

 extent from the conclusions already laid down by M. Gruby. M. 

 Malassez says that it is constituted of minute spores, of which he 

 describes three types: — (1) Those which measure from 4 to 5 mm. 

 have a double contour and may possess buds : these are the large 

 spores. (2) Those measuring from 2 to 2 • 5 mm. have no double con- 

 tour, and may have buds : these are the small spores. (3) These have 

 an inferior diameter about 2 mm., have a single contour and no buds : 

 these are the sporules. He says that the ovoid spores that one some- 

 times sees do not belong to this fungus, but most probably to some 

 other one. There are no tubes, but sometimes little chains of five or 

 six or even more spores. These results difier from those of M. Gruby 

 chiefly in the absence which they record of branches and stems, which 

 are described by M. Gruby to be .present. 



TJie Zoological Position of the Hypojms is very clearly defined in a 

 memoir by M. Megnin in the ' Journal de I'Anatomie ' (No. 3, May, 

 1874). These animals belong to the acari class of beings, and are 

 parasitic (so-called) on nearly every animal, from the common house- 

 fly upward. M. Megnin discusses their relations to each other, their 

 anatomy and their habits, and comes to some interesting conclusions ; 

 among others, that these animals are not truly parasitic ; for he says 

 that the animal on which they are situated merely acts as a " dis- 

 senmiatar and preserver of their species." This paper is accompanied 

 by four good plates, in which several species are figured in their 

 mature and immatm-e conditions. 



The Structure of the Skiri. — Dr. P. H. Pye-Smith gives an excellent 

 survey of the recent work in this direction, which has been done by 



* 1874, Zehnter B;m<l Drittcs Heft. 



t See Max Schultze's ' Archiv,' 10th Bund, 3rd Heft. 



