2 Psyche [April 
stomachs of the birds and experiments made as a direct result of these. 
Thus Bau has found in the stomachs of jays (Eichelhiher) egg-masses 
of Malacosoma neustria (German ‘Vent caterpillar), eggs of Orgyia 
antiqua (German 'Tussock moth), eggs of Psilura monacha (the 
‘‘Nun”’ of the Germans), together with eggs of other Bombycid moths. 
He has proved by various experiments that all these eggs pass out 
undigested, protected by means of their extremely hard chitinous 
shells and remain in a living state. Therefore the author naturally 
concludes that birds even help to propagate injurious insects. In this 
way Bau’s experiments furnish an explanation for the sporadic dis- 
tribution of the gypsy moth, which is, as is known, a close relative 
of the European Psilura monacha. Dispar eggs have exceedingly 
strong chitinous shells also, which are undoubtedly resistant in the 
same manner against the decomposing action of the digestive juices 
of the birds’ stomachs. 
THE GREEN Bua anp its NaTurAL Enemies, A Stupy IN INSECT 
Parasitism. By S. J. Hunter. Bull. Univ. Kansas, Vol. 9, No. 2, 
pp. 163, figs. 48, Pls. 9, October, 1909. 
This extensive paper deals with the relations existing between 
Toxoptera graminum, the Green Bug and its parasite, Lysiphlebus 
tritici, and deals in great part with the successful artificial dissemina- 
tion of the parasite in Kansas. It contains however, much good 
biological matter concerning both species, particularly the parasite 
which was extensively studied experimentally with regard to its 
variation, reproduction, habits at different temperatures, etc. Much 
is added to our knowledge of the bionomics of Lysiphlebus, and one 
remarkable conclusion reached is worthy of special mention. It was 
found that parthenogenetic Lysiphlebus produce almost entirely males, 
but that a very small proportion of females regularly appear among 
such offspring. Unfortunately the report contains a considerable 
amount of controversial matter and numbers of detailed tables are 
printed at great length where it would seem that short summaries 
might have served the purpose much better. 
Cw, B. 
