298 NATURAL SCIENCE [November 
opaque layers and network being due to the formation of slime or 
jelly by the bacteria themselves, or (2) that it is due to symbiosis 
between the bacteria and some gigantic rhizopod, the protoplasm of 
which is seen in the floceulent layers and network. After discuss- 
ing these two views, Dr Dendy calls attention to the marvellously 
close resemblance of Pontobolbos to the enigmatical fossils Stromato- 
poridae. The paper appeared in the Linnean Society’s Journal, 
volume twenty-six. 
‘BueGs’ as Foop 
Mr G,. W. Kirkatpy, who has been devoting his attention for some 
time to the systematic description of the Rhynchota, has written a 
short note to the Hntomologists’ Monthly Magazine (p. 173) on 
arrangements which have been made for the importation into this 
country both of imagines and ova of Notonecta and Corixa in large 
quantities for the food of insectivorous birds, game, fish, and others 
with peculiar tastes. It has long been known that the natives 
of parts of Mexico eat the perfect insects with relish, and that the 
sale of cakes made of the ova is fairly extensive. The species to 
be imported, according to Mr Kirkaldy, are Notonecta americana, 
Fabr., and Coriza mercenaria, Say. The ova are called by the 
Mexicans ‘ Axayacatl’ or ‘waterface’ and are made into cakes 
with the addition of meal. These are eaten au naturel or with 
ereen chilies. If cooked without meal they are called ‘ ahuanhtli’ 
or ‘ water wheat, have the appearance of fish roe, have a delicate 
flavour, and are not disdained at fashionable tables. Virlet d’ Aoust 
indeed compared them to caviare. Mr Kirkaldy, however, cannot 
speak highly of them as a relish, his were stale and tasted of 
sulphuretted hydrogen and decayed animal substances. The perfect 
insects, moreover, had a distinct ‘buggy’ flavour. Still one can 
educate one’s palate, and there are some who revel in the pope’s 
nose of a goose despite its taste of cockroach. The C. mercenaria 
are imported by the ton, and each ton is imputed to contain 250 
millions of insects. We will not dine with Mr Kirkaldy. 
THE RELATIONSHIPS OF BUTTERFLIES 
READERS of Natural Science will recall Mr A. Radcliffe Grote’s 
papers at the beginning of the present year (vol. xu. pp. 15-26, 
87-99) on the classification of butterflies according to the wine- 
neuration. His main contention was the separation of the Papil- 
ionidae from all the other butterflies on account of the presence of 
a short vein (ix.) next to the inner margin of the forewing, this 
vein being absent in all the other families. In a recent paper 
entitled “ Specialisations of the Lepidopterous Wing; the Pieri- 
Nymphalidae,” in the Proc. Amer. Phil. Soc. (vol. xxxvii. pp. 17- 
