20 



have certainly found all these together, except G. ^jriniijer, in the 

 spring. 



There are two other species in the genus, viz., G. vemaliy and 

 G. pi/ri')iaeufi, but these I have not yet found and therefore can say 

 nothing about them at present. Of the first mentioned insects the 

 only one which lays its eggs in autumn is G. spinit/er, and it 

 continues right on into December, and, as far as I can make out, 

 the beetles then die ofi" in January. I have found a number of dead 

 ones in the field then, and certainly one does not come across any 

 alive again till the following autumn, when the beetles, originating 

 from the ova laid in the preceding winter, come to maturity. 



G. mutator emerges in the autumn, but does not commence egg- 

 laying till the following spring, and the resulting beetles appear in 

 the autumn of the same year. 



G. steirorariits emerges in the autumn, commences egg-laying in 

 the following spring, but the resulting beetles only appear in the 

 autumn of the succeeding j'ear. This was surmised by M. Sano in 

 his paper, and I find that larvie from ova laid last spring (1916) are 

 going over the winter nearl}^ full grown and will, therefore, be out 

 next autumn (1917), while ova of G. imitator deposited at the same 

 time all produced the beetles last autumn (1916). 



Concerning (t. ti/p/ioeKs I am not yet quite clear. Beetles taken 

 in the autumn of 1915, did not commence to lay till the spring of 

 1916, and all the resulting larvae appeared to be full grown in 

 December, but none have yet pupated (January, 1917). According to 

 Fabre, the beetles should have appeared last autumn, but tempera- 

 ture may have something to do with the difference in the rate of 

 development. 



G. si/lraticiis has been the most difficult to get to oviposit, and I 

 have to make further investigations with this species before saying 

 much about it. It certainly is found abundantly in the autumn, 

 and again in the spring, at which time it commences egg-laying. 

 1 have only one larva and that is passing the winter quite small. 



It is exceedingly interesting to watch the division of labour 

 between the male and female beetles when making the cavities and 

 filling them with food for the larva\ The female is the skilled 

 worker, the male the labourer-'. It is she who excavates the chamber 

 at the bottom of the shaft, while he takes the earth up to the sur- 

 face to get rid of it. As he pushes a small mass up the shaft he 

 rotates, making a quarter turn each time followed by a vigorous 

 heave. In the cages, it is necessary to remove the earth brought 

 up to the surface to prevent accumulation, and when it is seen that 

 the food-chamber is about ready, some fresh horse-dung is put into 

 the top of the cage. The male carries down the food and the female 

 takes it from him at or near the bottom of the shaft, carries it in, 

 and rams it into the end of the chamber. She is very particular 

 about the way the various layers of material are added, and goes 

 through a wonderful series of gymnastic feats in the process of 



