The Microscope. 357 



whereupon a union occurred and immediately the two blended into 

 one. The smaller animal appeared to flow into the larger, and to 

 disperse itself thi'ough it in a manner which is common to all these 

 animals, young as well as full grown, and which will be described 

 later, when we reach a nearly mature heliazoan. Before the union 

 of these two animals, they appeared alike, except in size and num- 

 ber of vacuoles; but shortly after the union, the granules in the 

 protoplasm gradually moved towards the center of the animal, 

 where they became more numerous, and instead of being evenly dis- 

 tributed throughout the granular protoplasm, now formed a central, 

 more granular portion, with an outer, clearer and less granular zone. 

 Three more rays were also developed, and the animal presented the 

 appearance shown in Fig. 7, which, at this stage, would probably 

 not be mistaken for any other species. Hundreds of individuals 

 were to be found of this size and appearance, and hence it was not 

 necessary to watch the development of this single individual longer, 

 as other fields promised better results. 



There was almost an unlimited supply of heliazoa intermediate 

 in size between the two whose union produced the one just men- 

 tioned. They diflPered in no respect from one another, or from the 

 two just mentioned, except a slight difference in size, and every gra- 

 dation between them was to be found. Merely for the sake of filling 

 up the gap which exists in regard to size between the two individ- 

 uals whose union we just referred to, I will cite one example out of 

 many which I have observed. Two similar individuals, slightly 

 larger than the smaller (Fig. 26) of the two just united, were seen 

 to come together (Fig. 22), and, as a result of their union, a helia- 

 zoan was produced, so nearly alike the larger (Fig. 25) of the two 

 of the former individuals, that there was, practically, no difference 

 between them. 



Another field was now chosen, in which were a number of heli- 

 azoa, similar in all respects to the one representing our last stage 

 (Fig. 7). I had not waited long before it was evident that two of 

 these animals were gradually approaching one another, from some 

 cause which I was unable to discover. When within a very short 

 distance, — in fact, almost ready to meet, — there occurred a very 

 singular movement on the part of both individuals — a movement 

 which I can hardly account for — in which there was produced a 

 swelling, as it were, in that part of the sphere of both animals (Fig. 

 8, 9) which was just about to toiich the other, and by continued 

 enlarging with increased rapidity, soon met one another, thus unit- 



