196 M. F. GUYER AND E. A. SMITH 
of the crystalline lens. Inasmuch as the lens is relatively large 
in the eye of the rabbit, it seems legitimate to infer that the small 
size of the affected eyes, recorded in a number of cases, is due 
primarily to total or partial inhibition of growth of the lens. 
And since in its origin the lens is concerned so intimately, both 
mechanically and probably also chemically, with changes in the 
optic cup, it is not unreasonable to attribute such malformations 
as open choroid fissure resulting in cleft iris (coloboma), irregular- 
ities in distribution of retinal blood-vessels and of blood-vessels 
of the eyeball, abnormal postures of the eyeball, and flattening 
of the eyeball, as likewise due primarily to initial abnormali- 
ties in the lens. The occasional persistence of the hyaloid artery 
obviously points to an arrest of development of the whole lens 
apparatus at a well-recognized stage of its formation, since this 
artery together with a plexus of blood-vessels which invests the 
lens, though normal structures at one period of lens development, 
should atrophy and disappear once it is constructed. 
One other fact should be mentioned, namely, that in pulping 
and injecting the lenses, undoubtedly small amounts of the 
aqueous and of the vitreous humors were carried over also since 
no special effort was made to eliminate every trace of them. It 
is probable, therefore, that the sensitized fowl sera included to 
some extent antibodies for these humors. ‘This opens up the 
possibility that they, too, may have played some part in the eye 
deformations, although we have had no visible evidence that 
such was the case. The one central phenomenon in all the eye 
defects is the opacity of the lens—sometimes homogeneous, some- 
times pebbly, sometimes flaky in appearance—together with its 
diminution in size. 
The first thought that occurs to the embryologist, of course, is 
that perhaps the abnormal condition is due to just a general 
poisonous or inhibitive effect of a foreign serum upon the devel- 
oping fetus or upon a specially sensitive part of it, theeye. From 
the well-known work of Stockard (’09, ’14) and others, the eye, 
at its inception at least, is known to be particularly susceptible 
to deleterious chemical influences. In the present instance, how- 
ever, if the effect is a general one, then it should be as readily 
