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HARDWICKE'S SCIENCE-GOSSIP. 



At this season 'of the year I have frequently found 

 the habitats of Polyzoa, by means of their floating 

 statoblasts, in ponds where I had not seen them 

 before, and by searching the same ponds during the 

 next summer and autumn have been often successful 

 in finding the mature animal. 



I may mention here, that the Lophopus aystallinus 



on the 25th of March of the same year, 1875. The 

 opening of the statoblast is very curious and interest- 

 ing, and resembles a bivalve shell (which opens like an 

 oyster) from which the little animal protrudes and 

 soon forms a tube and grows rapidly into a colony. 

 The Cristatella mucedo usually break up and die during 

 the month of October, when the statoblasts are 



Fig. 45. — Cristatella mucedo, enlarged, showing polypes. 



is an exception to this rule, as we have always found 

 it fully developed in the winter and spring and not in 

 summer and autumn. It is very remarkable that 

 this naked form should live and thrive in the cold 

 weather, whilst the tubed forms break up and die upon 

 the approach of winter. It is, I think, doubtful if all 

 the statoblasts come to the surface of the water after 

 the disintegration of their tubes, as I have found those 

 of Alcyonella fungosa firmly attached to the dead 



numerous, very beautiful, and quite different from any 

 of the other species. They are circular, and have a 

 number of anchor-shaped spines projecting from them, 

 which evidently serve for attachment to the stems of 

 weeds upon which they grow. 



A colony placed in my aquarium late in October 



Fig. 46. — Cristatella mucedo, naf. size. 



sticks upon which these spongy-looking masses grow, 

 and surrounded by fluffy decomposing debris. 



Those which float probably remain on the surface 

 until the time arrives for development, when they 

 would attach themselves to any floating weeds or 

 rootlets. I have found Fredricclla sultana very plenti- 

 ful in September, and a few alive early in November, 

 when the tubes were full of statoblasts, some of which 

 placed in my aquarium developed on the nth of 

 February following, and more hatched early in March, 

 and some very young forms were found in the canal 



Fig. 47. — Fredericella sultana, nat. size. 



rapidly decomposed, when the statoblasts were sur- 

 rounded by a semi-transparent oval sac which floated 

 to the surface, and in time liberated the statoblasts 

 which became free and floated on the water. 



None of these developed, owing, probably, to the 

 want of natural surroundings. 



The development of Paludicella Ehrenbergi is to 

 me ! the most wonderful, and is altogether the most 



