COLLECTION OP BDELLOID AND OTHER ROTIFERA. 219 



that necessary for the Fontinalis group of mosses. Sphagnuni 

 should not be washed roughly in the net, it is too fragile for 

 that method. It is better to simply squeeze handfuls into the 

 net, and it is also useful in suitable places to turn up one's sleeve 

 and plunge a bottle deep down among the long roots and there 

 fill it with the water and to empty it into the net a few times. 

 Sphagnum frequently harbours several species of Ploima, and 

 especially members of the family of Cathypnidae, even when it 

 is not growing in or alongside a pool. The swimming species 

 are most plentiful in Sphagnum growing in bog pools, and are 

 mostly species which rarely or never occur in the ordinary 

 pools and ditches. The rotifer worker should make a point of 

 searching Sphagnum wherever he finds it growing. The results 

 of moss squeezing should be examined as soon as possible, as 

 the swimming species are mostly delicate forms which do not 

 live well in confinement. Sphagnum should also be brought 

 home, and if lightly packed in a metal box will keep in good 

 condition for some weeks. It should not be squeezed before 

 packing, and it must not be allowed to get dry. I think it best 

 to wash it in very small quantities when making a stock, and 

 treating it comparatively gently. I have also had good results 

 from packing it fairly tightly in a bottle, adding sufficient water 

 to thoroughly soak it. When I desired to examine it, I shook 

 the bottle and then poured some of the water into the stage 

 trough. But with this method there is some risk of the 

 Sphagnum fermenting, with fatal consequences to all Kotifera. 

 Wet mosses from dripping rocks or wet banks should be dealt 

 with in the same way as the dry mosses to which I next refer. 

 They should be stored in metal boxes or in bottles, and not 

 allowed to become dry. 



Mosses which grow in positions usually dry should not be 

 gathered during rain or even shortly after being wetted by rain 

 or dew. They can be kept either in metal boxes or in paper 

 bags. The grease-proof paper now so generally employed 

 makes a good wrapping for small packets. 



The possibility of getting living rotifers from dry material is 

 a consequence, fortunate for the microscopist, of the wonderful 

 capacity of certain Rotifera of retaining their life in spite of 



