8o 7he Effem of Airl 



Polypes feem not to want much Airi 

 Numbers of them were brought from Hb/- 

 land in Glafs-Veffels clofely llopp'd; and I 

 have known them carried about (in the 

 Pocket) whole Days, in a Phial corked clofe, 

 without receiving any Harm. Thofe in my 

 own little Glaffes have conftantly been locked 

 up in a Book-Cafe, and yet have thriven much 

 better than others kept more open: which 

 perhaps is owing to the kindly EfFedl Heat 

 has on them, as plainly appears by their be- 

 ing reftored much quicker after Cutting, and 

 producing young Ones in greateft Abundance 

 when the Weather is at the hotteft. 



In Summer Time, however, they may 

 be kept in any Sort of Veffels, or in any 

 Place ; but when the Weather is cold, fmall 

 Glaffes covered with Paper, having only a 

 few Pin-Holes pricked through it, and pla- 

 ced in a warm Clofet or Cabinet, are beft : 

 and in a frofty Seafon proper Care muft be 

 taken to prevent their being frozen. They 

 remain commonly at fuch Times contract- 

 ed, unlefs when brought to a warmer Air : 

 require cleaning and feeding much feldomer : 

 appear more fluggifh and unadlive, and breed 

 but feldom : and as all their Operations are 

 much (lower, their Reprodudlion, after Cutt^ 

 ing, takes up then likewife a much longet 

 Time. 



It 



