76 TOILERS IN THE SEA. 



close relationship to it, called the Sun-animalcule, 

 or Actinophrys. It is through this little creature 

 that some knowledge may be obtained of the 

 animal of the Polycystins ; indeed it might almost 

 be termed a Polycystin without a shell. The body 

 is spherical, and is of that peculiar jelly-like con- 

 sistence already described in the Amoeba, from which, 

 however, it differs in not being so variable in shape, 

 not suffering such continual changes, but retaining 

 its globose form and also in the more slender 

 threadlike pseudopodia which radiate from the body 

 in all directions. Dr. Carpenter remarks that " in 

 Actinophrys the pseudopodia are very numerous, 

 and, when fully extended, are long, slender pro- 

 cesses, that gradually taper from base to point, and 

 issue from the body in a radial direction ; they 

 generally remain distinct, when they come into 

 mutual contact, never undergoing that complete 

 fusion which is common in those of the Forami- 

 nifera ; and a slow movement of granules may be 

 seen to take place along their margin, when the 

 observation is continued for a sufficient length of 

 time, under high magnifying powers." Although 

 several memoirs l have been written, dealing more 

 or less with these organisms, their history on many 



1 Kolliker : " The Sun Animalcule." Quart. Journ. Micr. 

 Sri.) vol. i. (1853), pp. 25, 98. Claparede, on "Actinophrys," in 

 Annals Nat. Hist," vol. xv. (1855), pp. 211, 285. 



