Digest of Current Literature. 245 



It merely plays the part of an organ of vegetation, and does not pro- 

 perly afford, by its presence or absence, any distinction of species. It 

 maj' furnish nutriment to the young diatoms, or serve to distribute 

 the species by dividing into parts which are carried off by the water. 



All genera founded upon the character of the thallus, form, con- 

 sistence, etc., should be abolished. 



The entire subject is well treated, and should be read by those inter- 

 ested in the study of diatoms. 



On THE Termination OF Nerves in the Striated Muscles. — 

 ¥rom Comptes Rendus. Vol. LXXXVII. 



The Oil-Immersion of C. Zeiss, &c.— Prof. H. L. Smith.— Trans- 

 lated from this journal. 



Microscopical Technic. — A chapter from a prize thesis by Mr. A. 

 Henocque, on the termination of the nerves in the unstriated muscles, 

 relating to the application of the gold method in histology. This 

 method has been used by the author since 1870. 



January, 1879. 



The Muscles of the CEsophagus. — Prof. Ranvier. 



Researches on Spermatogenesis. — Dr. Mathias Duval. These 

 studies were carried on in some pulmonary gasteropods. The article 

 begins with some general considerations, and closes with the study of 

 spermatogenesis-in Helix. It is illustrated with a plate. 



The spermatozoids originate in this way : During December, the 

 walls of a cut de sac of the hermaphrodite gland of a helix is lined 

 with epithelial cells, among which larger, distinctly nucleated, cells 

 are to be seen. These are called the mother cells. Soon the nucleus 

 becomes opaque and granular, loses its spherical shape, and numerous 

 smaller nuclei form in the protoplasm. By a process very similar to 

 budding, these nuclei become centers to numerous smaller cells, which 

 remain attached to the mother cell. It is from these that the sperma- 

 tozoids are formed. The article is not completed in this number. 



Angular Aperture of Objectives. — Dr. George E. Blackham. 

 Continued. 



Diatoms of the East Indian Archipelago. — Continued, with 

 plate. 



Histological Microscope. — Description of a Stand of Ch. Collins. 



Researches of Van Tieghem on Mucorines. — A biblio- 

 graphical note. 



THE AMERICAN JOURNAL OF MICROSCOPY. 



December. 



What can be done with a Cheap Microscope. — From Young 



Scientist. The Microscope in Medicine. — Dr. S. M. Mouser. Read 



before the San Francisco Microscopical Society. The Use of the 



Microscope. — Dr. Geo. E. Blackham. The Microscopical Ex- 



