356 The Microscope. 



explanation is that, as indicated, the protoplasm of the two animals 

 is exactly alike, and, hence, there can be no need of digestion. Were 

 one of the heliazoa dead when it came in contact with another which 

 would otherwise have fused with it, I have no doubt but that the 

 dead heliazoan would be surrounded and drawn into the interior of 

 the live one, the same as other animals are, and there digested, it 

 being not exactly alike the protoplasm of the one which is alive. 

 For if this were not the case, if the dead heliazoan, upon contact 

 with the living heliazoan, were to form a jDart of it, as the living 

 heliazoan did, then we should have a case where simple contact of 

 the living protoplasm with the same, but dead protoplasm, would 

 impart life to the dead, just as a piece of iron, which is magnetized, 

 if brought in contact with one which is not, will impart magnetism 

 to it. But it is needless to say that such a phenomena of life has 

 never been observed. 



While watching the heliazoan (Fig. 3, 20) which we have just 

 described as being the result of the union of two of the youngest 

 individuals, (Fig. 2, 23), the water was stirred by a worm, and 

 another heliazoan, of about the same size as the one under observa- 

 tion, but with three vacuoles and no rays, was brought nearer and 

 nearer, until finally they accidentally came in contact with one 

 another and immediately united (Fig. 20) and assumed a spherical 

 form. Presently the single ray disappeared, and three more vacuoles 

 made their appearance in the mass of protoplasm, together with the 

 development of a contractile vesicle (Fig. 5). This individual was 

 watched until it had developed three rays and several more vacuoles 

 (Fig, 6), a process requiring about twenty-five minutes, during 

 which time it had eaten nothing except one of the youngest heliazoa 

 without a vacuole. Under the one-twelfth oil immersion I was able 

 to detect the axis cylinder in two of the rays, but not without some 

 doubt in the third ray. 



Very near this individual (Fig. 6, 26) was another heliazoan of 

 a much greater size (Fig. 25), and by touching the cover-glass with 

 a needle, I soon brought the two so near that the tip of one of the 

 rays of the smaller heliazoan touched the larger animal. Wishing 

 to observe the result of this contact, I waited a few minutes, when 

 it became apparent that the smaller individual was drawing in its 

 ray which was in contact with the larger heliazoan, and was thus 

 drawing itself towards it. The larger animal, offering the greater 

 resistance, did not appear to move. Five minutes from the time the 

 ray first touched the other heliazoan, the two had come in contact. 



