508 E. I. WERBER 



into two hemispheres. This is very striking on comparison of 

 figure 64 with figure 65. Both ilhistrate sections of approxi- 

 mately the same region. While in the former (the case of bilentic 

 synophthalmia described above) the separation of the two hemi- 

 spheres is very distinct, in this cyclopean embryo (fig. 65) there 

 is an apparent rupture of the solid brain mass caused evidently 

 by the expansive growth of the eye which it tightly encloses. 

 This is a break rather than a natural division and it can be fol- 

 lowed throughout the entire mid-brain, while the hind-brain is 

 distinctly bilobed. No other abnormalities were found in this 

 embryo. 



These data suggest that the ovum at an early stage of its 

 development has sustained an injury at the anterior end of the 

 future embryo's chief body axis. The injury apparently con- 

 sisted in a destructive elimination of a small, very sharply pointed 

 wedge of tissue (the point directed posteriorwards), comprising 

 the future interocular area, possibly a small part of the opthal- 

 moblastic material, and, evidently, also a considerable part of 

 the future brain. The coalescence of the wound surfaces has 

 caused an approximation and subsequent fusion of parts, which 

 in turn eventually resulted in cyclopia. 



The other case of synophthalmic cyclopia concerns an embryo 

 (fig. 12) (p. 490) whose head exhibits some striking features. It 

 is relatively very small (microcephalus) , the mouth is a wide 

 open, typical proboscis and the eye is single, median in position, 

 very large and betrays on examination in toto no evidence 

 whatever of being composite in character. 



In anterior sections of this embryo (fig. 66) the appearance 

 of a normal, transversely sectioned, eye is presented, and the 

 synophthalmic character is revealed only by examination of sec- 

 tions at a more posterior level. However, if the brain is exam- 

 ined in anterior sections the nature of the process is disclosed 

 to which the malformation secondarily owes its origin. The 

 forebrain is unpaired and very small, for, in size it hardly exceeds 

 that of the eye. The most remarkable feature, however, which 

 the brain at this level presents, is a fragment of retina which is 

 fused with it at its lower extreme right and just above the orbit 



