320 H. H. NEWMAN. 



I shall show only two types out of a very large number found 

 in lot C in which the slowing of the cleavage rate was most pro- 

 nounced. Fig. 13 shows a common type which is practically a 

 head without a body. The little up-turned stump is all there is 

 of the body; the heart is still beating; the eyes are in an advanced 

 stage of differentiation. Fig. 14 shows a case of solitary or 

 isolated eye. No other tissues are differentiated. I look upon 

 these as cases of recovery of the apical regions after rather severe 

 early inhibition. There is no hard and fast line to be drawn 

 between the three classes of monsters shown. 



It may be said in closing that each type of hybrid cross differs 

 from others in the particular array of monsters displayed. In 

 some there is never cyclopia, but always microphthalmia. In 

 some the extreme recovery types, like that shown in Fig. 13, are 

 much the most common. In many respects the F. heteroclitus 

 9 X mackerel cf cross is the best adapted for the study of the 

 morphogeny of teratomata because of the very wide range of 

 forms produced. 



In conclusion I wish to express my appreciation of the far- 

 reaching applications to morphogenetic phenomena of the axial 

 gradient idea as worked out by Child. Few generalizations 

 known in biological science serve to rationalize so wide a range 

 of developmental phenomena. 



BIBLIOGRAPHY. 

 Child, C. M. 



'15 Individuality in Organisms. The University of Chicago Press. 

 '16 Experimental Control and Modification of Larval Development in the 

 Sea Urchin in Relation to the Axial Gradients. Jour. Morph., Vol. XXVIII 

 No. i. 

 Kellicott, W. E. 



'16 The Effects of Low Temperature upon the Development of Fundulus. 



Amer. Jour. Anat., Vol. 20, No. 3. 

 McClendon, J. F. 



'iza An Attempt toward the physical chemistry of the production of one-eyed 



monstrosities. Am. Jour. Physiol., Vol. 29. 

 'i2b The Effects of Alkaloids on the Development of Fish (Fundulus) Eggs. 



Am. Jour. Physiol., Vol. 31. 

 Newman, H. H. 

 '08 The process of heredity as exhibited by the development of Fundulus 



hybrids. Jour. Exper. Zool., Vol. V., No. 4. 



'14 Modes of Inheritance in Teleost hybrids. Ibid., Vol. 16, No. 4. 

 '15 Development and Heredity in Heterogenic Teleost Hybrids. Ibid., Vol. 

 18, No. 4. 



