

228 [November, 



in one of these batches, consisting of forty-two eggs, thirteen de- 

 veloped, of which two hatched out, the larvae dying shortly afterwards. 

 Others seemed to have partly hatched, but most eventually perished 

 in the shell. At this time fertilized eggs were hatching in nine days. 

 It appeared to me that several of the thirteen were imperfectly or 

 monstrously developed ; one, for example, having only one mis- 

 shapen (?) mandible ; another, excess in number and irregularity in 

 grouping of the eye-spots, &c, &c. Again, on June 17th, I found in a 

 parcel of (twenty-five) eggs, laid June 6th — 7th, six which had de- 

 veloped up to the hatching. In the usual course, at the time of 

 hatching, the young larva comes out of the shell clear like barley-sugar, 

 but blackens afterwards ; in the case of these parthenogenetic larvae 

 which do not hatch out, this blackening takes place w r ithin the shell. 

 In a third batch, of over twenty eggs, laid June 8th, I found three eggs 

 similarly developed. In the meantime, aud afterwards, many dozen 

 batches had been laid, in which, however, I did not detect any 

 development. 



A second experiment miscarried ; but I was more successful with 

 a third and fourth. From a batch of eggs laid June 5th — 6th, I 

 derived pupae which on July 8th following I placed separately in pots, 

 and obtained from them thirteen beetles, of which seven turned out 

 to be females. About the same time I brought in from the fields some 

 well-grown larvae, the beetles from which were isolated immediately 

 after their exclusion, and subsequently yielded eight females. These 

 (seven and eight) were all kept in separate pots during the course of 

 the experiment. Of the seven no less than five laid eggs which after- 

 wards developed parthenogenetically. They laid as many as ten 

 parthenogenetic batches among them, but while some of them laid 

 three such batches, others laid only one. These were invariably the 

 first batches laid, and none of the batches laid subsequently contained 

 any viable eggs while the experiment lasted, which was in some cases 

 up to the tenth batch. Of the eight beetles of the fourth group, only 

 one laid one parthenogenetic egg in its first batch. The number of 

 parthenogenetic eggs in a batch varied from one to seven. In four 

 batches there was only one such egg ; in three batches five, and in the 

 other four batches two, three, six, and seven respectively. The total 

 eggs in a batch averaged 41'7, and as there were thirty-six partheno- 

 genetic, the proportion over all was 1 in 12^. However, as may be 

 supposed, the proportion in the individual batches varied very much, 

 one small parcel of only eleven eggs having as many as five developed. 



In most of these cases also the larvae perished in the shell. A 



