36 Eurtcnema Herculanea, Charpentier. 



and turning into grey in the later stages. Now they suddenly 

 appeared in a glistening new green skin, with long wings, and 

 the body seemingly almost double its former diameter. All 

 specimens were female, and a few weeks after they had reach- 

 ed the adult stage, they began to swell up and lay eggs, the 

 first of them being laid on September 16th. None of the fe- 

 males had ever come into contact with a male insect, having 

 been carefully kept in a large airy case consisting of glass and 

 perforated zinc, exhibited in the entrance hall of the Raffles 

 Museum. Eggs were continually being laid by the sister in- 

 sects up to February 1898, the insects dying about two or 

 three weeks after they had deposited the eggs. Of the eggs 

 laid during the last four months of 1897 and the first two 

 months of 1898, a careful account was kept. Every morning I 

 inspected the case, removed the eggs which had been laid du- 

 ring the past twenty-four hours, and placed the eggs laid on 

 different days in separate boxes, duly dated. The first young 

 ones of this generation appeared in March and the last in Au- 

 gust, requiring for their development from 105 to more than 

 240 days of which great divergence in time 1 cannot give 

 any explanation. Most of them, however, were hatched be- 

 tween the 195th and 212th days, the maximum number being 

 hatched on the 205th day. The accompanying table shows the 

 proportions of eggs hatched on different days. This generation 

 was rather weakly, only a few reached maturity, most of them 

 dying off when shedding their skin two or three stages before 

 maturity. The. first of the;n reached the adult stage on August 

 10th, 1898, and never having come into contact with any male, 

 began to lay eggs on September 15th. These eggs did not deve- 

 lop, and none of the other individuals of this generation laid 

 any eggs. 



The reason why the eggs of the last generation did not 

 develop was very probably in consequence of their artificial 

 surroundings. If I had been able to keep the insects in more 

 natural conditions and to devote more care to their feeding, I 

 feel sure I would have been able to rear a few more par- 

 thenogenetic generations. 



This appears to be the first instance of Parthenogenesis 

 observed amongst (Mhoptera, and there are now only three 



Jour. Straits Branch . 



