104 THE REPOET OF THE No. 30 



Fig. 8. Holeaspis bassetti Gillette on the stem of Quercus macrocarpa Michx. Sec- 

 tion through the gall cavity with enclosed larva. The character of the cells of the nutri- 

 tive zone is shown and the unbroken edge of the inside boundary. X^O^. 



Fig. 9. Section of a larval inquiline from the gall Holeaspis bassetti Gillette. The 

 broken edge of the tissue on which the larva has been feeding is shown, also the com- 

 paratively coarse material of the stomach contents. x^O. 



Fig. 10. Philonix nigra Gillette. Longitudinal section of the larva, showing the 

 external opening of the ailimentary canal. x^S. 



Fig. 11. Philonix nigra Gillette. Longitudinal section of the head of the larva pass- 

 ing through a salivary gland and its associated duct. The opening is just below the 

 mouth. x40. 



Fig. 12. Rhabdophaga strobiloides Walsh on the stem of S^alix cordata Muhl. Longi- 

 tudinal section, showing the larva in contact with the small-celled tissue at the apex of 

 the stem. x25. 



Fig. 13. Pontania hyalina Norton on Salix alba L. Section of gall with larva still 

 within the egg membrane. Proliferation is shown well advanced in all the tissues of 

 the leaif. X^5. 



ANTS. 

 (Abstract of Illustrated Lecture on "Ants," by Prof. W. M. Wheeler.) 



By way of preface the lecturer made some general statements in regard to 

 the 5,000 known species and sub-species of ants, and described the development 

 and metamorphosis of the individual ant, the various castes, or polymorphic phases 

 represented by each species and the function of each of these castes in the life 

 of the colony. Then the general behaviour of ants was treated from the stand- 

 point of the three basic biological activities, namely reproduction, nutrition and 

 protection. 



Special emphasis was placed on the behaviour of the female, or queen ant 

 «nd her methods of establishing the colony in contrast with the behaviour of the 

 queen honey-bee and with the male ant, which takes no part in the activities of 

 the colony as such, but functions only as a fecundating agency during the nuptial 

 flight. The queen ant was shown to possess all the instincts of the worker forms 

 in addition to some of her own and thus to represent the most complete embodi- 

 ment or epitome of the species. This statement requires qualification only in the 

 case of certain parasitic and slave making species, in which the queen is degenerate 

 like the queen honey bee and no longer able to establish a colony and bring up 

 the first brood of her ojffspring without the aid of workers either of her own or 

 of an alien species. 



The peculiar structure of the ant's alimentary tract was described in some 

 detail, with its "social" and "individual" stomachs, which enable the insects not 

 only to store their liquid food in the most economical manner but also to distribute 

 it equally among the various members of the colony both larval and adult. Eor 

 the purpose of illustrating this portion of the lecture more fully the various adapta- 

 tions of ants to living in very dry regions, such as deserts, were examined, and 

 it was shown that these insects have evolved four very different methods of 

 circumventing the difficulties inseparable from life under conditions that imply 

 a great scarcity of their natural insect food. A certain number of species have 

 exaggerated their primitive predatory instincts and have become rapacious hunters 

 (e.g. the species of Cataglyphis in the North African deserts). Others have taken 

 to storing quantities of liquid food in the crops, or social stomachs of certain 



