Zoologischer Anzeiger 



herausgegeben 



von Prof. J. Victor CarUS in Leipzig. 



Zugleich 



Organ der Deutschen Zoologischen Gesellschaft. 



Verlag von Wilhelm Engelmaim in Leipzig. 

 XIX. Band. 29. Juni 1896. No. 506. 



Inhalt: I. WissenBchaftliche Mittheilangen. 1. Parker, Pigment Migration in the Eyes of 

 Palaemonetes. 2. Bolsius, La glande susoesophagienne de la Eaementeria officinalis. 3. Schmidt, 

 Noch Einiges zur Phylogenie der Myriapodenordnungen. 4. de Man, Platychirograpsus spectabilis, 

 nov. gen. n. sp., eine neue Form der Orapsidae vom Gabun, Westküste von Africa. II. Jlllttheil. ans 

 Slnseeii, InBtitnten etc. 1. Volk, Eine neue Verwendung des Wasserstoif-Superoxyds bei mikrosko- 

 pischen Untersuchungen. 2. Academy of Natural Sciences of Philadelphia. 3. Die Biologische 

 Station za Plön. 4. Avis. 5. Demande. III. Personal-Notizen. Vacat. Bibliographia.p.301— 324. 



I. Wissenschaftliche Mittheilungen. 



1. Pigment Migration in the Eyes of Palaemonetes. 



A preliminary notice ^. 



By G. H. Parker, Instructor in Zoology, Harvard College, Cambridge, 

 Mass., U. S. A. 



eingeg. 23. April 1896. 



The following results were obtained from experiments made upon 

 Palaemonetes vulgaris Stimp. with the intention of determining the 

 character of the changes induced in the pigment of the retina by the 

 presence or absence of light and of ascertaining whether these changes 

 were dependent upon the action of the central nervous system. 



In the compound eye of Palaemonetes , each ommatidium consists 

 of the following parts: two corneal hypodermal cells (Fig. IjCr??.) closely 

 applied to the proximal surface of the corneal facet [cta.)\ a cone (cow.), 

 formed from four cells and occupying an axial position in the distal 

 part of the ommatidium; two distal retinular cells [cl.dst.), containing 

 black pigment and partly covering the sides of the group of four cone 

 cells; a rhabdome [rhh.), occupying an axial position in the proximal 

 part of the ommatidium and surrounded by seven proximal retinular 

 cells (cl.px.), each of which contains black pigment and, after passing 

 through the basement membrane [mb.ba.)^ extends as a retinal nerve 



* Contributions from the Zoological Laboratory of the Museum of Compara- 

 tive Zoology at Harvard College, E. L. Mark, Director, No. LXII. 



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