LECT. XI.] CAUL1NAR AND FOLIAR APPENDAGES. (583 



cause the faux in this species is covered by the 

 hood, and the light excluded. If the fly attempts 

 to crawl up, the inverted position of the hairs is a 

 sufficient obstacle to its escape. Spiders, a small 

 species of Phalaena, and some other insects which 

 enter these tlibes, appear, however, to ascend 

 without difficulty. 



I have, already, stated my accordance in the 

 opinion that these putrefying masses may be be- 

 neficial to the growth of the plant ; but this 

 conjecture, Mr. Keith observes *, " cannot be re- 

 " garded as quite satisfactory till such time as it 

 " shall be shown that the health of the plant is 

 " injured when insects are prevented from ap- 

 " proaching it." It is curious to observe, that 

 these fly-traps become serviceable to some indi- 

 viduals belonging to the very division of the 

 animal creation which they serve to destroy. 

 Dr. Macbride says, " in the putrid masses of 

 " insects thus collected, are always to be seen 

 " one or two maggots in a very active state." He 

 was unable, for some time, to ascertain the in- 

 sect to which these belonged ; " but while watch- 

 " ing attentively some tall tubes of Sarracenia 

 " flava growing in their natural situation, a large 

 V' he remarks, " caught my attention: it 



* Syst. of Physiol. Bot. vol. ii. p. 286. 



f This viviparous musca was more than double the size of 

 the common house-fly, had a reddish head, and the body hairy, 

 and streaked greyish. Lin. Trans. I. c 



