[.S6 



N. M. STEVEN- 



SPERMATOGONIA. 



As in nihrr vertebrates tin- tc>u-s om>Ut of much coiled 

 t.ulmle- in \\hich, in mature animal-. -Merman >.unua and Sertoli- 

 cfll- a IT found at the- periphery against the wall of the tulmle: 

 then coiiK 1 lirsi and sccoiul sprrniati H-\ it--^ in \-ari<.ii> stages, 

 -l>rrmatid>, and unri|)L- s])crmatozoa attached to long processes 

 r\ u-ndiiv^ from tin- Sertoli-cells toward tin- criitcr of tlic tulmle, 

 -|)i-niiato/().i licin- found in or near the lumen of the tubule. 



I-'H.. i . \u. l.'ii- i .| Sntiili ci-11. 

 !"[(.. j. Xiii \<-\i- i)i spermatogonium. 

 l-n;. 3. Spireme st.t^i-, -]> i in.it'>-( in iiim. 

 FK.S. .j anil 5. N'UI lei iinin .1 \niiiit; tc~iis, M--t--t,i.y>' ;nnl 

 FIG. 6. Fifty--i\ chromosomes <>t .1 -i" 1 ' ni;it"^n]ii.il 

 prep. 



P"!G. 7. Efjuatorial plaii- "i a -pi-i in.it, i^nnial mit(>M~; s' 1 'In ....... soincs. All 



1 1C i ' j - 



h- 



Aceto-carm. 



