THE ENTOMOLOGIST. 237 



of the male sex.' This obseivalion was undoubtedly made in 

 ignorance of the discovery made by Mr. Walsh in 1868. In 

 the 'American Naturalist' for that year, the author records 

 the fact of having himself bred both sexes of Cynips 

 spongifica from galls of the black oak of North America. 

 These galls resemble those of Cynips Kollari, being globular, 

 rather larger than the European galls, but of the same hard 

 woody consistency externally, and of the same spongy 

 substance inside. INIr. Walsh adds ; ' By the forepart or 

 middle of June both male and female gall-flies eat their way 

 out of a certain number, say about one-fourth part; the 

 remainder are not developed until about two months later.' 

 In a private communication from Mr. Walsh, I learnt that he 

 had, like myself, bred hundreds of the gall-flies from galls 

 collected late in the autumn, all these proving to be females; 

 and that it was not until he made collections of galls in the 

 summer, when a partial development of flies takes place, 

 that he obtained the male, this sex being as one to many 

 hundreds of females. At length he bred three males, one of 

 which he kindly forwarded to me, and which I exhibited at a 

 meeting of this Society. Following up Mr. Walsh's method 

 of collecting the galls of Cynips Kollari early in the season, 

 — that is, just at the time when they are becoming hardened, 

 and before any flies have escaped from the fresh galls, — 1 

 have tried, but hitherto without success, to obtain males of 

 Cynips ; but I advise all who are interested in the matter to 

 pursue the same plan, always remembering that these 

 mysteries of Nature are only unfolded at intervals, and then 

 only to favoured votaries. With respect to the obtaining of 

 males of Nematus gallicola, I believe that anyone may collect, 

 even early in the season, thousands of the galls of that insect 

 without obtaining a male; but, in all probability, by persevering 

 season after season, his efforts will, as in my own case, be 

 crowned with success ; but I feel assured that unless the 

 galls are gathered before any of the flies have escaped he will 

 have little or probably no chance of success. The same care 

 must also be taken in collecting the galls of Cynips Kollari; 

 collecting them early, just at the time when they harden and 

 become woody, for it is out of the flies first developed that 

 the male may be expected to be found. My having bred 

 thousands upon thousands ol flies without obtaining a male 

 should prove a stimulus to others, for that a male exists I 



