and Laboratory Methods. 1303 



Hence the motive force lies outside these structures. The structures are com- 

 pared with the supporting bones of a fish's fin, and a comparison is made to 

 bring out the resemblances caused, of course, by the similar mechanical condi- 

 tions. Finally, the author states his belief, that the ciliated cell apparatus, the 

 supportive structures of the mouth cirri of amphioxus and the blepharoplasts 

 of antherozoids are all similar structures. a. m. c. 



Regaud, CI. Quelques details sur la division I" 1^99 several articles were published 



amitotique des Noyaux de Sertoli chez le by the same author to show that the cells 



rat. Sort du nucleole Deux varietes r r- ^ i- t ^ i • i ^ •^- 



d'amitose: Equivalence ou non - equiva- of Sertoh do not play Simply a nutritive 



lence des noyaux fils. role for sperm cells, but are cells cap- 



Anat. Anz. Centralblatt f. d. Gesammte Wis- , , , .^ ^. i- • • 11 



sen. Anatomie. Erganzungsheft zum xvii able of amitotic division, and hence 

 Bd., 1900, p. 110-124, 15 fig. im text. of producing spermatogonia. The 



evidence for this is based not only on the nuclear figures clearly amitotic, but 

 also on observations on the stages of development of the spermatogonia and on 

 transition forms of nuclei between those of the Sertoli cell and the spermatogonia ; 

 finally on the impossibility of explaining the renewal of spermatogonia by the 

 karyokinesis of the other cells present. The method used for the study of 

 chromatic parts of the seminal epithelium, is a double stain of hsematoxylin and 

 safranin. This process gives very good results after fixation in Baum's picro 

 aceto-formol mixture, and Lenshossek's of sublimate alcohol and acetic acid. 

 The most exact results follow the use of Tellyesniczky's bichromate of potash 

 and acetic acid. The sections are stained rather deeply with alum haematoxylin, 

 then washed in water. If the sections appear too deeply colored under an 

 immersion lens in water without a cover glass, decolorization follows with an 

 aqueous solution of formic acid (1-100). Washing in ordinary water restores 

 the blue color. After this the sections are stained for twenty-four hours or 

 more in Zwaardemaker's solution of safranin. A rapid washing in water is 

 followed by decolorizing in ninety per cent, weakly acidulated alcohol (1 HCl- 

 1000 Ale). The safranin is removed, but the haematoxylin is unaffected : 

 neutral ninety per cent, alcohol is followed by absolute and then xylol and 

 Canada balsam. If the two stains have acted with just equal intensity, a con- 

 dition easily obtained by practice, the cytoplasm is stained a pale rose-violet 

 and the chromatic parts are very intensely colored, sometimes a purple-violet, 

 sometimes a red-purple, sometimes intermediate between these colors. The 

 chromatic granules in the accessory nucleolus of the nucleus of the Sertoli cells, 

 the surface chromatin of the spermatogonia and young spermatocytes, the chro- 

 matin of the nuclear mass of the spermatocyte during the first part of their 

 development, the nucleus of the spermatids during first period of their transfor- 

 mation into spermatozoa, are all colored a violet-purple. The extra nuclear 

 chromatic bodies of the spermatocyte and spermatid, the nucleolus of the nucleus 

 of Sertoli cells, certain parts of the nuclear chromatin of the spermatocyte 

 (body of Lenshosse'k at certain stages), the nucleolus of the spermatocyte, the 

 nucleus of the spermatid during the last period of transformation, etc., are 

 colored a red-purple. Intermediate between these are certain chromatic bodies 

 of the young spermatogonia and the chromatin of the nuclear filament of the 

 spermatocyte in certain stages. During the karyokinesis of spermatogonia their 



