254 Transactiojis of the Society. 



or four weeks. The sides of the vase were then covered with 

 vegetation. The sea-water was poured away, and the few ounces 

 of sea-salt with the proper proportion of water put into it. The 

 result was somewhat surprising. Three male Artemia hatched 

 out, but no females. 



In view of the generally received opinion that sex is predeter- 

 mined in the egg, the conditions under which they were hatched 

 could hardly be responsible for the appearance of male Artemia 

 only. Some fresh specimens of sea-salt from Trepani, and also 

 some from Mahdia in Tunis have lately been sent to me, and with 

 these I hope to make some further experiments. 



In the male of Artemia there is also to be seen a remarkable 

 development of the second antenna. In the three males reared, 

 these antennae were always seen folded under the body during life, 

 but for the purpose of showing them satisfactorily, they have been 

 mounted fully extended, and may be seen in slide N"o. 12. 



It only remains for me to thank Mr. Lees Curties very much 

 for enabling me to bring these specimens to your notice. 



