TESTICLE-CELLS OF FUNDULUS 135 



polychetes: the granules in many species are consistently four in 

 number, their form being exactly spherical, their volume equal 

 and their disposition around the proximal part of the tail per- 

 fectly regular. 



The origin of these bodies is briefly referred to by Retzius 

 ('04 a and b) who states (for molluscs) that the large spheres are 

 formed by the confluence of smaller granules. Previously, Pic- 

 tet ('91) and Field ('95) both had described the formation of the 

 so-called 'mittelstiick' in the spermatozoon of echinoderms 

 through fusion of highly refractive granules which, however, they 

 erroneously derived from remnants of the spindle. 



Quite recently M. R. Lewis ('17) has stained the chondriosomes 

 (the so-called 'middlepiece') of the spermatozoon of Cerebratulus 

 lacteus and of Echinorachnius parma in vivo, by using a solution 

 of Janus-green in sea-w^ater.- 



The object of the present investigation is the testicle of Fun- 

 dulus (heteroclitus and majalis), the main purpose being to 

 study the behavior of the chondriosomes during spermatogenesis. 

 The material was collected in Woods Hole, Mass., in June, 1916, 

 and fixed in Regaud's or in Benda's fluid, the latter either with or 

 without acetic acid. The sections, 5 n thick, were stained in the 

 first case with iron-haematoxyhn or acid f uchsin-methylgreen ; 

 after Benda's fixation, I resorted to iron-haematoxylin acid, 

 fuchsin-methylgreen or Benda's stain, the lattef giving, as previ- 

 ously stated for embryos ('17), a very small percentage of good 

 preparations. A number of sections were stained with safranin, 

 hi order to study the chromatin. 



Once more I found that the preservation of the tissue is 

 much better after Benda's fixatian than after Regaud's. This 

 last reagent has a pronounced tendency to make the seminal cells 



2 In the same paper, M. R. Lewis (p. 33) quotes my opinion, as expressed in 

 my review ('12j, on the vital staining of chondriosomes and, from this quotation, 

 one might be induced to conclude that, for me, neutral red and methylenblue 

 can be used or have been used to stain the chondriosomes in vivo. To prevent 

 any misunderstanding, I wish to recall that this has never been my opinion, as 

 appears clearly in the quoted place of my article (p. 608), as well as in several 

 others (for example, page 823, in the discussion of Arnold's plasmosomes). 



