498 



E. I. WERBER 



tion known in human teratology as synotia. Not infrequently, 

 however, the ear vesicles may be unusually small, and in such 

 cases on microscopic examination it may be found that the semi- 

 circular canals are very defective, rudimentary or diminutive in 

 size or that one or two of them may be lacking altogether. 



Not many embryos could be tested for their capacity of main- 

 taining the equilibrium while moving about, since few of them 

 would hatch if the eggs were treated with butyric acid or acetone. 

 However, upon several of them, which did hatch, the observa- 

 tion was made that they could swim only in circular or spiral 



Fig. 42 Asymmetrically monophthalmic embryo, with club-tail, without pec- 

 toral fins. On the yolk-sac at a distance from the embryo is seen an isolated 

 tissue fragment t.f., and an isolated eye i.e., from acetone solution (40 cc. gram 

 molec. to 50 cc. sea-water), twelve days old. 



Fig. 43 Asymmetrically monophthalmic embryo with isolated eye, i.e., from 

 acetone solution (25 cc. gram molec. to 50 cc. sea-water), sixteen days old. 



Fig. 44 Amorphous embryo, in toto making the impression of malformed 

 coalesced twins, from acetone solution (25 cc. gram molec. to 50 cc. sea-water), 

 tM^elve days old. 



lines, or along the wall of the fingerbowl in which they were kept, 

 while they could not move in a straight forward direction, 

 dropping at once to the bottom of the dish, if forced to do so. 

 This functional anomaly agrees well with the structural defects 

 of the semicircular canals spoken of above. 



2. The amorphous embryos 



This group extends over a wide range of monstrous embryos. 

 It begins with forms which on examination in toto in their shape, 

 size and structural peculiarities only faintly suggest the resem- 



