V CHROMOSOMES IN MAN. 223 



matoxylin method. However, the number, twenty-four, which 

 he records for in. in was not 'determined by direct count but was 

 intVrn-d i'r>m tl that he found two or three clear cases of 



Ive hromo-imit - in the primary spermatocytes. That his 

 find in-.: "t t \\i-l\r in the primary spermatocytes was comvt is 

 l...rm- MUI by in rvations but he is not justified, in con-r- 



qm-iiri-. in -i.ttin- i hat there must be twenty-four in SJKTIU.I- 



nial <>r -om.ni. nil-divisions. My material shows that 

 two "t tin- lui-Kr chromosomes are the univalent accessor 

 and a cl< int of favorable spermatogonial chromosomes 



n \i-.d- .>nly t\\ -nty-two. This means in all probability that 

 I' iln i \\d\i- c hromosomes of the primary spermatocyte, 

 .in lii\.iltni .Mul two accessories. Although Duesberg examined 

 tin- spermatogonial chromosomes he states that he was unaliK- 

 to ' "inn tin-in \.niK U-yond determining that, contrary to 

 the i|iiniuii of \'on Hardrlt-U-n. there were clearly more than six- 

 teen. II' : I- - lunhi i p. 477) that, "Je n'ai pas pu les compter 

 rx.u i. UK nt. taut ;\ i-aii-r de la petitcsse dcs cellules qnr du 

 iioml.iv assez -1<\. dr- chromosomes, mais dans quelqucs cas 

 l.i\ o|-.iMi - .,11 li-ur iniii u a pu el re tMitreprise, j'ai obtenu 



dr- n-uli.ii^ trrs M>i-iu> dc 24, jamais sup6rieurs ;\ ce nombre 

 d.in- lr- n llules normales." And in conclusion he says: "II r- 

 Miltrdr l.i i |iu lr nombre des chromosomes est certainement a mon 

 a\ i-. di- u dan-, les sj)ermatocytes et par cons6(juent de 24 dans 



;permatogoni< U-- illules somatiques. C'est la confir- 



matiiin dc ri|iininn dr I Innniin^." 



In i In 'o-iu-r.il > h< nir of the s|K-rmatogcnesis of man there ap- 

 |n-ar> IK In- in >i hin- unique. One can readily recognize the usual 

 fniir m 'in -r. uio n- n i-i-IU; viz., spermatogonia, primary sper- 



in. r i -|K rniai'n ytcs of the first order), secondary sper- 



matocytes "i ~\ mi.ii,>. \ tes of the second order), and la>il\ 

 spermatids which transform directly into the spermatozoa. An 

 abundant' i-il\ identified Sertoli or nurse cells are in evi- 

 dence. < '< > a-imal centrosomes were observed in suitably stained 

 pri'i>aratii'ns Inn I have not pictured any in my drawings U-- 

 cause the preparations from which the latter were made were all 



'K-nJx d<-( i ilori/rd that the stain had evidently o>m])K-ii-l\- 

 di-.ip|u .IK d I'mni an\ centTOSOmes which mi^hi ha\v Urn |>iv-nn . 



