644 T^^^^ Ainencan Nahiralist. [July. 
Arthropoda. — M. Nussbaum has seen two polar globules in the 
cirripede egg {Zool. Anzeiger, 301). The first is formed while the ^gg 
is in the ovary, the second after fertilization in the egg sac. 
Vertebrata.— Dr. R. W. Shufeldt publishes (^Journal Comp. Med. 
and Surg., Apr. 1889), an account of the osteology of the hawk, Cir- 
Mr. S. Garman (Bulletin Essex Institute, XX.), has collated the refer- 
ences to the Batrachia in the various editions of Kalm's Travels in 
North America. The result is to overturn some of the nomenclature 
of our frogs and toads. 
EMBRYOLOGY. 
Homologues in Embryo Hemiptera of the Appendages 
to the First Abdominal Segment of other Insect Embryos. 
— While preparing a paper on the appendages of the first abdominal 
segment of the embryo Blatta gennanica for the Proceedings of the 
Wisconsin Academy of Sciences, Arts and Letters, to be published 
during the coming summer, my attention was drawn to the Hemiptera, 
on which no observations have as yet been made in regard to append- 
ages to the first abdominal segment. The pair of appendages which 
appear on this segment in embryo Orthoptera, Coleoptera and Tri- 
choptera remain short, but become bulbous, and persist in some cases 
till the larva hatches. All investigators agree that in these three orders 
the curious appendages reach their greatest development during the 
revolution of the embryo. They have been regarded by Rathke, Ayers, 
and Graber as embryonic gills, by Patten and myself as glands. 
The two species examined by me were Cicada septemdecim and Nepa 
cinerea, which represent two of the three large divisions of the 
Hemiptera. 
In both cases the appendages persist as in the Orthoptera till after 
revolution, but instead of being ^vaginated as in the insect embryos 
heretofore investigated, they are /maginated. The shape of one of 
these appendages is bulbous, and its pyramidal cells are radially ar- 
ranged with their broader basal ends turned inwards and their taper- 
ing outer ends terminating on the surface of the body. In Cicada 
there are few cells in the organ, in Nepa a much greater number. 
In Cicada a glairy, much vacuolated mass is secreted by the tapering 
outer ends of the cells, and projects into the space between the body 
