ACTINOPHRYS. 13 



posits brought up by the sounding-lead from the bottom of the Atlantic 

 Ocean at depths of from 1000 to 2000 fathoms. They appear to have 

 been much more abundant, however, during the later geological periods, 

 inasmuch as in a single deposit in Barbadoes, Professor Ehrenberg 

 detected no fewer than 282 forms which he considers to be specifically 

 distinct. 



(28.) ACTINOPHEYS. Among the most interesting contributions to 

 our knowledge of these simple organisms are those of the distinguished 

 German micrologist Kolliker, whose researches relative to the organiza- 

 tion of Actinophrys /Sol* are calculated to clear up many doubtful points 

 connected with the physiological history of numerous allied genera of 

 kindred structure. The Actinophrys (fig. 5, l) is a minute animalcule 



Actinophrys Sol. 1. a, the cortex; b, nucleus of the animalcule; c, homogeneous basal sub- 

 stance ; d, vacuoles; e, tentacular filaments. 2. The same, less magnified, at the moment of feed- 

 ing: a-e, as above; f, an infusorium which has just entered the substance of the body, while the 

 surrounding filaments enclose it on all sides. 3. Another specimen : a-e, as in fig. 1 ; f, a Vau- 

 cheria-spore wholly imbedded in the cortical substance, the opening through which it entered 

 entirely closed, although its situation is indicated by a slight depression ; g, another spore already 

 entering the nuclear substance ; h, an infusorium lying in a special cavity ; i , a spore in the nuclear 

 substance ; k, half-digested morsels ; I, a swallowed Lynceus ; m, excrementitious matter beginning 

 its exit from the cortical substance. The other figures represent the sarcode highly magnified. 



nearly spherical in its shape, having the surface of its body covered with 

 closely-set delicate filaments, the length of which frequently exceeds 

 the diameter of the creature. It does not present a trace of mouth, 

 stomach, intestine, or anus, but consists entirely of a perfectly homo- 

 geneous substance of soft and delicate consistence. Examined under 

 a very high power, the whole animalcule appears to be made up of a 

 most regular and delicate tissue of round or polygonal cells, although 

 on closer inspection such is found not to be really the true structure. 

 When the animal is torn or crushed, it becomes evident that it is entirely 

 composed of a semifluid material (sarcode) enclosing vacuoles; for it 

 will be found that the supposed cells may at pleasure, under pressure, 



* Siebold and Kolliker's Zeitschr. vol. i. p. 198. 



