PLATE 1 



EXPLANATION OF FIGURES 



All figures were drawn with the aid of a camera lucida, using a 4 mm. objective 

 and ocular no. 4 with tube length of 165 mm. except figure 9 for which ocular 

 no. 6 was used. 



1 A section through the center of a tumor develojjcd in a fly after inoculation 

 with tumor-cell suspension. 



2 A section through the center of a tumor develoi^ed in a meal worm after 

 inoculation with tumor-cell suspension. 



3 A section through the dorsal imaginal rudiments showing tumor develop- 

 ing in the two anterior rudiments. 



4 Same, with the tumor fully developed in posterior rudiment. 



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