358 STATE HORTICULTURAL SOCIETY. 



The researches of Drs. Dallinger and Drysdale on the life history of one of 

 these organises, only 1-5,000 of an inch in length, furnishes a good illustra- 

 tion of the vital activity of particles of matter that were invisible under the 

 highest powers of the microscope. They observed the ordinary process of repro- 

 duction by fission until it seemed to be the only mode of multiplication, but by 

 watching an individual continuously for five days and niglits they were finally 

 rewarded by witnessing a true sexual reproduction, and the formation of 

 spores. 



The process of conjugation consisted essentially in the fusion of two individ- 

 uals into one, forming a " spheroidal glossy speck " which was kept constantly 

 in sight. After a variable time, sometimes ten hours or more, " the sac — for 

 such it is — opens gently, and there is poured out a brownish, glairy fluid. At 

 first the stream is small, but at length its flow enlarges the rift in the cyst, and 

 the cloudy volume of its contents rolls out, and the hyaline film that encloses it 

 is all that is left. The nature of the outflow was like that produced by the 

 pouring of strong spirit into water. But no power that we could employ," 

 says Dr. Dallinger, "was capable of detecting a granule in it. To our most 

 delicate manipulation of light, our finest optical appliances and our most riv- 

 eted attention, it was a homogeneous fluid and nothing more. Fixing * * * 

 a lens magnifying 5,000 diameters upon a clear space, over which the fluid was 

 rolled, and near to the exhausted sac, * * * in the course of a hundred 

 minutes there came suddenly into view the minutest conceivable specks. I can 

 only compare the coming of these to the growth of the stars in a starless space upon 

 the eye of an intense watcher in a summer twilight. You know but a few minutes 

 since a star was not visible there, and now there is no mistaking its pale beauty. 

 It was so with these inexpressibly minute sporules ; they were not there a short 

 time since, but they greio large enough for our optical aids to reveal them, and 

 there they were." 



" In an hour and ten minutes from their first discovery they had grown to 

 oval points. In an hour more the specks had become beaked and long, and 

 this pointed end was universally the end from which the flagellum emerged. 

 With the flagellum comes motion, and with that, abundant pabulum and, 

 therefore, rapid growth. But when motion is attained we are compelled to 

 abandon the mass, and follow one in all its impetuous travels in its little world. 

 And by doing so we are enabled to follow the developed speck into the parent 

 condition and size, and not to leave it until it had, like its predecessors, entered 

 on and completed its wonderful self-division by fission." 



In this world of microscopic forms we have an example of one of those 

 wonderful compensations in nature which excite our admiration and mark the 

 perfection of vital activities. What these minute beings lack in size is fully 

 made up by their astonishing powers of reproduction and multiplication. 



Dr. Colin has made an estimate that the produce of a single individual, if 

 all are supposed to multiply by fission at the rate they have been observed to 

 do under the microscope, would fill the oceans of the world completely full, to 

 the depth of one mile in five days. Fortunately, however, but a small pro- 

 portion of these minute organisms find the necessary conditions for their 

 development and increase and the balance of nature is therefore maintained. 



In the study of this world of life in its simplest forms, special methods are 

 required together with appliances especially adapted to the purpose. 



A microscope with objectives of the most perfect construction, capable of 

 magnifying from 500 to 3,000 diameters will be needed for their investigation. 



