ORIGIN OF MONSTERS 495 



nation of sections of his monsters Spemann ('04, p. 433) finds 

 that the 'Kieferbogenfortsiitze' are "in der Mitte zu eine^n ver- 

 schmolzenJ'^ That the defects of the mouth are syngenetic 

 with those of the eyes is well suggested also by such embryos 

 where the eyes are small and in a very imperfect condition and 

 the mouth exhibits an anomaly analogous to the 'hare lip' or 

 'cleft palate' of man (figs. 18 and 19). 



This syngenesis of defects of the head is further suggested by 

 the 



c. Defects of the olfactory pits. The condition of these organs 

 in teratophthalmic embryos is strikingly similar to the defects 

 exhibited by the eyes. All degrees of approximation and blend- 

 Fig. 18 Alicrophthalmic embryo with 'hare lip,' from acetone solution (35 

 cc. gram molecular to 50 cc. sea-water), thirty-one daj-s old, px. pericardial 

 vesicle. 



Fig. 19 Like 18, twenty-four days old. 



Fig. 20 Microphthalmic embr3'o without fins, with club-tail, from acetone 

 solution (40 cc. gram molec. to 50 cc. sea-water), thirteen days old. 



Fig. 21 Microphthalmic embryo, Avith 'proboscis'-shaped mouth, supernu- 

 merary lens, S.I., and one pectoral fin only, p.c, pericardial vesicle. 



Fig. 22 Embryo with one lateral rudimentary eye, free lens, I. on eyeless 

 side, oedamatous ear vesicles and a supernumerary pectoral fin, s./., from ace- 

 tone solution (40 cc. gram molec. to 50 cc. sea-water), thirty-four days old. 



Fig. 23 Anophthahnic embryo without fins and with club-tail, from acetone 

 solution (35 cc. gram molec. to 50 cc. sea-water), twelve days old. 



Fig. 24 Anophthalmic, malformed embryo with rudimentary pectoral fins 

 and club-tail, from acetone solution (20 cc. gram molec. to 50 cc. sea-water), 

 fourteen days old. 



Fig. 25 Greatly malformed embr3'o, with small eyes, without fins, from 

 acetone solution (35 cc. gram molec. to 50 cc. sea-water), twelve days old. 



Fig. 26 Amorphous, oedematous embryo, with rudimentary eyes, from ace- 

 tone solution (40 cc. gram molec. to 50 cc. sea-water); fourteen days old. 



Fig. 27 Deformed embryo, with short posterior part of body and rudimentary 

 eyes, from acetone solution (35 cc. gram molec. to 50 cc. sea-water), thirteen days 

 old p.c, pericardial vesicle. 



Fig. 28 Greatly malformed, elongate embryo with waist-like constrictions, 

 with one vestigial eye and club-tail, from acetone solution (35 cc. gram molec. 

 to 50 cc. sea-water), thirteen daj'S old, p.c. pericardial vesicle. 



Fig. 29 Greatly malformed embryo, with waist-like constrictions, one median 

 rudimentary eye, rudimentary pectoral fins, club-tail and a very small isolated 

 eye, i.e., on yolk-sac, from acetone solution (40 cc. gram molec. acetone to .50 

 cc. sea-water), thirteen days old. 



■* My own italics. 



