HARD WIG £1*8 SCIENCE-GOSSIP. 



107 



reference to its mode of swimming. It, I may say, 

 always carries its pectoral fins at right angles with 

 the body. These fins are constantly in motion 

 when the fish is moving about, while the posterior 

 half of the dorsal fin only is in motion, in connection 

 with the tail, as the guiding fins. The ventrals do 

 not seem to be used at all when the fish is swim- 

 ming, but, with th? pectorals, are used as legs when 

 the fish comes to a rest on -the mud or any smooth 

 surface. I have frequently watched them slowly 

 settle down upon the smooth sand in the aquarium, 

 with the tips of the pectorals and ventrals just 

 touching the surface. The folded anal fin was close 

 to the body of the fish and scarcely noticeable. In 

 connection with the position of the body and fins 

 above described, I must mention a constant habit 

 of curving the body, sometimes doubly like a letter 

 S, and more frequently like a J. When in such a 

 position, with the fins utilized as legs, one is forcibly 

 reminded of a salamander, or that link between 

 them and fish, and I doubt not myself but this use 

 of the fins, together with this habit of curving the 

 body, and preference for liquid mud rather than 

 water, all are initial steps of an upward movement, 

 which we correctly call evolution. If it is not 

 permitted us to see the complete evolutionary 

 process of the origination of a new species, I 

 cannot but think a careful student of Nature will 

 catch an occasional glimpse of it in the varied 

 phases of life that constantly surround him, if he 

 but make the effort. 



Trenton, New Jersey, U.S. A. 



REMARKS ON ACTINOPHRYS SOL. 

 By James Etjllagak. 



THE Actinophrys Sol is one of a remarkable 

 group of Protozoa. It has a circular figure, 

 but the distinctive peculiarity of its figure is due to 

 the filaments or tentacles, which radiate from all 

 parts of its surface, and give the creature, to employ 

 a familiar and not inapt illustration, the appearance 

 of a ball of cotton stuck thickly over with needles, 

 points outwards. These tentacles or filaments are 

 usually pretty regularly and uniformly distributed 

 over the entire surface, and in shape taper from the 

 base to the apex. The tentacles exceed in length 

 the diameter of the body, and at times are rendered 

 so rigid that animalcules moving rapidly through the 

 water, coming in contact with them, become en- 

 tangled by or impaled on them. When this 

 entanglement has not taken place, even the larger 

 infusoria, on coming accidentally 'within their reach, 

 start back with the greatest rapidity, sometimes 

 even dragging the Actinophrys Sol a considerable 

 distance with them. 



I had often seen these beautiful minute creatures 

 in the cells, where I had other objects of interest 



under observation, but never supposed that there 

 was so much in the study of their economy to render 

 them so interesting. I had seen numbers of them 

 with their bright rays or spines extended, — very 

 pretty objects they were, — and on some occasions 

 had seen their manner of absorbing their food, con- 

 sisting of small bodies of various shapes ; but in 

 this instance I was surprised to see that they were 

 able to seize and to swallow, or more properly to 

 absorb, a living animalcule longer in its body than 

 their own diameter, and to make use of their spines 

 or tentacles to secure and hold their prey in a way 

 that would bespeak a sort of intelligence far above 

 what we could expect in such a creature. For 

 though the Sun-animalcule was a large one, yet the 

 animal it had seized was large and powerful, and 

 in its struggles for liberty twisted and turned the 

 Actinophrys half round backwards and forwards. 

 The violence thus exercised appeared sufficient to 

 break the delicate tentacles by which it was being 

 held, or to drag it away altogether. This the 

 Actinophrys appeared sensible of, and in order to 

 prevent such a thing, it drew together a number of 

 the spines or tentacles, and brought the united 

 points of them in two different places, and fixed 

 them tightly to the glass. The spines appeared to 

 amalgamate and form into two large cone-shaped 

 spines (fig. GO, a a), the tips of which were flattened 

 on the glass and bent to and fro as the prey strug- 

 gled to escape. 



It is evident there is something that renders the 

 tentacles so powerful as to hold on to bodies or 

 other substances so firmly; whether from some 

 sticky matter exuding from them, or from the 

 presence of hooks or barbs upon them, is not 

 apparent. Another thing observed was, that some- 

 times when an infusorian, in its travels through the 

 water, accidentally became entangled with the 

 tentacles, it for a moment appeared paralyzed, and 

 ceased to move; but iu a few seconds it began 

 slowly and gradually to recover from the shock, and 

 finally made its escape from the tentacles. This 

 can be accounted for only on the supposition that 

 the Actinophrys was not hungry, or that it was not 

 the proper food, and so rejected it. 



In fig. Gj, b, the Actinophrys Sol is shown in its 

 usual form, and also (at c) the first contact of an 

 infusorian with its tentacle, when the struggle for 

 liberty on the one hand, and for a meal on the 

 other, commences. The A. Sol, in this instance, 

 had seized a Melopida Lepachella, which put forth 

 all its power to disengage itself from its relentless 

 foe ; but for all the efforts of Melopida to escape, it 

 still gradually approached the surface of its de- 

 stroyer (fig. GO, d). The food being thus far con- 

 veyed by the action of the tentacles to the surface 

 of A. Sol, the spot thus reached becomes slightly 

 depressed, it gradually becoming deeper, as the 

 victim is slowly absorbed into the body. A small 



