210 



VITAL STAINING AND MORPHOGENETIC MOVEMENTS 





10 







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2>^: 



11 



BLASTULATION IN AMBLYSTOMA FOLLOWED BY MEANS OF STAINING AT STAGES 3 OR 

 4 WITH NILE BLUE SULPHATE AND DISSECTION OF EMBRYOS AT STAGES 1 1 TO 33. 



{J. S. Nicholas 1945: Jour. Exp. Zool. 100:265) 



8 



1. Intense stain applied at stage 3j polar ingression; no stain coming through blastopore. Dissected at stage 1 1. 



2. Light stain applied at stage 2; polar ingression; stain covers whole area with greatest intensity near center of archenleron. 

 Compare with fig. 1 where intercellular material has been stained. 



3. Polar ingression with secondary transmission of stain applied at stage 4. Blastocoelic concentration of stain visible. Dorsal 

 lip stained, lateral lips unstained. Dissected at stage 12. 



4. Polar ingression with secondary transmission of stain applied at stage 4. Thin band of material from the yolk endoderm 

 extends forward and meets the primary stream. Dorsol lip stained, lateral lips unstained. Dissected at stage 12. 



5. Medium -heavy stain applied at stage 5. During staining the vegetal region was eccentric and lateral lip material was 

 stained, the central chordal region was not stained. Dissection at stage 13. 



6. Stain applied at stage 8. All of the stain coming into the archenteron through the blastopore. Dissection at stage 12. 



7. Heavy stain applied at stage 4. Barker mass blackened represents the results of the primary, the posterior the secondary stain 

 poth. The apparent diffusion of the secondary stain is due to the dissection in which the gut canal was opened. Dissection 

 at stage 24. 



Medium stain applied at stage 3. The gut canal has been opened. The stain is in the lining and the inner layer of the gut 

 cells. Dissection at stage 26. 



Medium stain applied at stage 4. Gut canal opened. Dissection at stage 27. 

 Medium stain applied at stage 3. Gut canal opened, dissection at stage 30. 



11. Light stain applied. Stain in liver region, partial diffusion. Lateral dissection at stage 33. 



