ARTIFICIAL PARTHENOGENESIS IN FROGS 273 
with the blood and immediately punctured, will develop, while 
the same eggs squeezed out from the female frog will not develop 
(when punctured).” Bataillon states that in the eggs thus 
treated ‘‘he found at the beginning of the divisions outside the 
kinetic figures, chromatin fragments accompanied by asters, 
which fragments come probably from elements inoculated with 
the needle.”! In a recent paper Bataillon reaches the conclu- 
sion that it is the leucocytes which cause the development (1913). 
A number of authors have succeeded in repeating these 
experiments by Guyer and Bataillon, Dehorne,? Henneguy,® 
Brachet,* MecClendon,? and Loeb and Bancroft.6 The last 
named, however, have produced tadpoles also without the use 
of blood or lymph. 
While the number of eggs which begin to segment when 
punctured is not inconsiderable, very few reach the tadpole 
stage. There is a difference in the response of the eggs of 
various kinds of frogs to this treatment. 
The number of unfertilized eggs which began to segment 
after puncture was according to Loeb and Bancroft greater in 
the wood frog than in the leopard frog, and amounted in the 
most favorable cases to about 40 per cent in the former. Only 
2 of about 10,000 punctured eggs of the wood frog reached the 
tadpole stage, but these died before they were able to swim. 
The percentage of eggs of the leopard frog which reached the 
tadpole stage was greater. From 700 punctured eggs of the 
Southern leopard frog, 13 good morulae were isolated the next 
day. On the third day, when the fertilized controls were in the 
1 Bataillon, ‘“‘La parthénogénése expérimentale des amphibiens,’’ Revue 
- $énérale des Sciences, XXII, 786, 1911; Compt. rend. Acad. Sc., CL, 996, 1910; 
CLII, 920, 1911; CLII, 1120, 1911; CLII, 1271, 1911; CLVI, 812, 1913; Arch. 
de Zool. expér. et gén., XLVI, 103, 1910. 
2 Dehorne, Compt. rend. Acad. Sc., CL, 1451, 1910. 
8’ Henneguy, Compt. rend. Acad. Sc., CLII, 941, 1911. 
4 Brachet, Arch. de Biol., X XVI, 337, 1911. 
5 McClendon, Am. Jour. Physiol., X XIX, 298, 1911. 
6 Loeb and Bancroft, Jour. Exper. Zool., XIV, 275, 1913. 
