296 PROCEEDINGS OF THE ACADEMY OF [Apr., 



lute alcohol, chloroform, and glacial acetic acid, with corrosive 

 sublimate to excess). For embedding, the double method of cel- 

 loidin and paraffin was employed. Serial sections cut six and ten 

 microns thick were stained with Ehrich's hamatoxylin and oesin. 

 For further details in regard to technique the reader is referred to 

 the writer's work on the honey bee. 



The writer is indebted to the following persons: to Messrs. J. C. 

 Crawford, H. L. Viereck and S. A. Rohwer of the U. S. National 

 Museum and the Bureau of Entomology for all the dried specimens 

 used; to Mr. Rohwer the writer is particularly grateful for the 

 systematic arrangement and names of most of the specimens included 

 in the table, pages 330 to 334; to Mr. Theo. Pergande for identifying 

 the ants used; to Miss Mabel Colcord for assistance in obtaining 

 references; and to Emma Pabst Mclndoo, the writer's wife, for 

 translating some of the foreign works. 



A. THE OLFACTORY SENSE OF ANTS AND HORNETS. 



In order to keep ants in the laboratory, several modified Fielde 

 ant nests were constructed. Colonies of various species were con- 

 fined in these nests. The behavior of the ants in the nests was 

 carefully studied and this behavior was used as a standard for 

 judging the behavior of all the ants used singly in the various experi- 

 ments. Many females of Camponotus^ were found in rotten stumps 

 and logs in the woods. Some of them had no eggs, some had only a 

 few eggs, while others had several eggs, a few larvae, and a few pupae. 

 Each female with her own brood, if brood was found in her nest, 

 was put into a honey-bee queen cage. This cage is 3| inches long, 

 2| inches wide and f inch deep. 



To study the behavior of one colony of Formica ohscuriventris 

 Forel in surroundings more natural than those afforded by using Fielde 

 nests, a large glass cage with four compartments was constructed. 

 The nest portion of the cage was 10 inches long, 10 inches wide and 

 16 inches tall. The entrance of the nest was 10 inches long, 10 inches 

 wide and 8 inches tall. This compartment was raised 8 inches above 

 the table so that one end of it connected with the upper half of one 

 side of the nest. The run-way was 8 inches long, 4 inches wide and 

 1 inch deep. This was also supported 8 inches above the table. 

 One end of it connected with the distal end of the nest entrance and 

 the other end connected with the fourth compartment, the manger. 



* Here as elsewhere in this paper unless otherwise indicated is meant the 

 large brownish variety of Camponotus pennsylvanicus Say. 



