a) 
72 ARTIFICIAL PARTHENOGENESIS AND FERTILIZATION 
fully matured and ready for fertilization. Many eggs after six or 
eight days showed upon sectioning that they had approximated the 
full blastular and in some cases the gastrular stages, although the 
condition came about apparently by some sort of internal nuclear 
arrangement, as no superficial cleavage furrows were observable and 
no demarkation into cells was visible from the exterior until the third — 
or fourth day, when close inspection showed in some cases numerous 
small vesicular or cellular outlines. 
In some instances definite organs were developed, though fre- 
quently distorted and misplaced. Cross-sections of one embryo, for 
example, showed such pronounced defects as two neural tubes an- 
teriorly. Of the whole number of eggs operated upon only two devel- 
oped into free-swimming tadpoles and these were apparently normal 
as far as superficial examination disclosed. They have not yet been 
sectioned. After sixteen days one died and the other was killed to 
insure proper fixation for histological study. 
Apparently the white rather than the red corpuscles are the stimu- 
lating agents which bring about development, because injections of 
lymph, which contains only white corpuscles, produce the same effect 
as injections of blood. Whether or not the fluid part of the lymph or 
blood produced any effect could not be definitely determined from the 
material at hand. 
Guyer thought that probably the cells which he intro- 
duced were developing and not the egg. He did not recognize 
that his experiment was a case of artificial parthenogenesis. 
This, however, does not detract from the fact that he was 
the first to cause the development of the unfertilized egg of 
the frog by puncturing it, that he introduced blood into the 
egg for this purpose, and that he succeeded in producing two 
parthenogenetic tadpoles. 
Guyer’s results were to a large extent confirmed by Batail- 
lon. Bataillon found that mere puncturing of the egg of the 
frog by a very fine needle could not produce any embryogenesis 
but that a second factor was necessary, namely, that some of the 
body liquids (blood of the frog or newt or fish) have to enter the 
egg. “A considerable percentage of the eggs of Rana, touched 
1 Guyer, Science, X XV, 910, 1907. 
