ZOOLOGY — CRAMPTON. 223 



land, have been completed and an adequately illustrated manuscript will 

 shortly be ready for publication. 



(2) Considerable time has already been given to the investigation of cer- 

 tain parasitic Hymenoptera, with a view to determining the precise conditions 

 of parthenogenetic reproduction in them, to producing hybrids, and to ascer- 

 taining the conditions of the chromatin during reproduction. This material 

 is found to be more available and more easily controlled than that of verte- 

 brates, so that for the present more attention will be given to the inverte- 

 brates. In this work Dr. Mark expects to have the assistance of one or more 

 students during the coming year. While the first cost of this material is 

 slight, the need of large numbers of preparations necessitates the employment 

 of expert technicians to prepare microscopic slides. 



Dr. Mark believes that this work will be of much theoretical value, and 

 may possibly lead to the solution of practical questions in the propagation of 

 parasitic Hymenoptera to control noxious insects. 



Crampton, Henry E., Columbia University, New York, New York. Grant 

 No. 431. The study and collection of gasteropod mollusca of the genus 

 Partida. (For previous report see Year Book No. 6.) $3,000. 



Dr. Crampton reports that in May, 1908, a second journey was undertaken 

 to the Society Islands, to extend the field of investigation so as to include the 

 leeward islands of the group. Eleven weeks and more were spent in actual 

 field work. 



In all about 40,000 specimens were taken from 95 valleys and stations in 

 the islands of Raiatea, Tahaa, Huaheine, and Borabora. More than 1,000 

 specimens were also procured from certain important valleys of Tahiti, pre- 

 viously explored. Therefore there is now in hand abundant material for a 

 thorough statistical examination of the variation of species of the genus 

 Partula inhabiting the Society Islands, where the greater number of known 

 species of the genus may be found. Each island that possesses Partulse has 

 been explored, and a special study has been made in each case of variation 

 and its possible relation to environment, in respect to climatic, geological, 

 physiographic, and heterogeneric biological conditions. Of special importance 

 is the availability of the material for the comparison of the snail faunas of 

 neighboring islands, separated by different degrees of distance. Tahiti and 

 Moorea are 10 miles apart and Raiatea and Tahaa are four miles apart, but 

 they are encircled by a common coral-reef, while Huaheine is a double island 

 whose two halves nearly touch. Moorea and Tahiti are 70 miles from Hua- 

 heine, the nearest member of the leeward group, while Borabora is 20 miles 

 beyond Raiatea. Therefore the snails of the various valley systems of these 

 couples or groups may be compared in the study of a larger distributional 

 problem as well as with respect to their variation within the island limits. 



