SECT. ii. THE ACANTHOMETRA. l g 



it tears out portions and conveys them to improvised 

 vacuoles to be digested. Dr. Wallich mentions that 

 he had seen nearly the half of a large Actinophrys 

 transferred piecemeal to the interior of its enemy, where 

 it was quickly digested. 



As every part of the body of the Actinophrys is 

 equally capable of performing the part of nutrition, 

 respiration, and circulation ; and as in the absence of 

 muscles and nerves they may be presumed to have no con- 

 sciousness, the marks of apparent intelligence can only 

 be attributed to a kind of instinct, and their motions 

 to the vast inherent contractility of the sarcode and its 

 enclosing film., which is also the case with the Amoebse. 



The Acanthometrse (see fig. 88, Acanthometra bulbosa) 

 are all marine animals ; their skeleton consists of a nurnr 

 ber of long spicules which radiate from a common centre, 

 tapering to their extremities. These spicules are tra- 

 versed by a canal with a furrow at the base through 

 which groups of pseudopodia enter, emerging at the 

 apex. Besides, there are a vast number of pseudopodia 

 not thus enclosed, resembling those of the Actinophrys 

 in appearance and action. The body is spherical, and 

 occupies the spaces left between the bases of the spicules. 

 The exterior film covering the body seems to be more 

 decidedly membranaceous than that of the Actinophrys, 

 but it is pierced by the pseudopodia which radiate 

 through it. This exterior film itself is enclosed in a 

 layer of a less tenacious substance, resembling that of 

 which the pseudopodia are formed. There is a species 

 of Acanthometra (echinoides) extremely common in 

 some parts of the coast of Norway, which, to the naked 

 eye, resembles merely a crimson point. 



The Polycystina are an exceedingly numerous and 

 widely dispersed group of siliceous rhizopods. They are 

 inhabitants of the deep waters, having been brought up 

 from vast depths in the Atlantic and Pacific oceans, 



C 2 



