404 Journal of Applied Microscopy. 



and stomatodaeum ; hence there is no entodermic portion. In these points the 

 autlior corroborates the worlc of Heymons. a. m. c. 



Tichotnirow, A. Zur Anatomie des Insecten- The testis of the silk moth consists of 

 hoden. Zool. Anz. 21 : 623-630, 5 figs., 189S. ^- ^- ^ 1 1, 



■^ -^ -^ " connective tissue stroma and germ cells. 



The stroma is arranged to form a sheath with a septa, and between there is a 

 delicate network of connective tissue strands subdividing the cavities formed by 

 the septa. " Verson's " cell appears above each of the four chambers as a local- 

 ized spot in the connective tissue bridges, where the tissue is richly supplied with 

 plasma. On later maturation of the spermatocytes a connective tissue cell 

 becomes transformed into a Sertoli cell, giving clear evidence on the different 

 tissue origin of this much discussed structure from that of the spermatozoa. 



A. M. c. 



Faussek, V. Ueber die Ablagerung des Pig- The Lamellibranch Mytilus was princi- 

 mentes bei Mytelus. Zeitschr. f. wiss. Zool. ,, j • 4.1 • ■ ^- ^- j ^u 



65: pp. 1 12-142, 3 figs., 1898. pally used in this investigation, and the 



most important conclusion is that pig- 

 ment formation is entirely independent of light. By removing one of the shells 

 it was found that light caused no access of pigmentation to the exposed surface, 

 but the controlling factor seems to be the amount of oxygen present in the water 

 flowing over the surface. By changing the direction of the water flow so that it 

 washed the anterior part of the body before it passed over the posterior, pigment 

 was formed in the anterior, normally colorless region. The author concludes that 

 pigmentation is due to the oxidation of a chromogen present in the blood, and 

 therefore the part of the body having the largest amount of oxygen supplied to it 

 is most deeply pigmented. a. m. c. 



Meek, A. Further note on the Post-Embryo- This is a reply or criticism of the work 

 nal History of Striped Muscles in Mammals. j 1 t-» -n tv/t ^1 



Anat. Anz 15: pp. 474-466, 1899. '^°''^ ^^ ^''- .^- ^orpurgo on the mus- 



cular tissue in white rats. (Reviewed 

 in Journal of Applied Microscopy, February, 1899.) The present author pub- 

 lished a preliminary report on some studies containing diametrically opposite 

 results in one respect. (Anat. Anz. 14: p. G19, 1898.) In the present reply he 

 adds several further observations. The point in question is the post-embryonic 

 multiplication of muscle fibers. By reference to Morpurgo's paper it will be seen 

 that in white rats there is, after birth, mitotic division of the muscle elements, 

 and hence an actual increase in the number of fibers ; two succeeding stages 

 follow, amitotic increase in the number of nuclei, and increase in the size of the 

 fibers. Meek had before demon.strated a reduction in the number of fibers after 

 birth. His observations have been carried on in the cat, sheep, and field vole 

 (Arvicola agrestis). His results in each case showed a reduction in numbers of 

 fibers, and hypertrophy of those remaining. Several different muscles from 

 different parts of these animals were examined, also some from the white rat, 

 and the results were uniform. The author admits that considering the very 

 immature condition of the latter at birth, there may be a continuance of certain 

 foetal processes after birth in some muscles. The reduction he finds occurs 

 more markedly in females than males, and while in young individuals the two 



