A UTHOR'S IN VES TIG A TIONS. I 3 7 



or less confluent, and thus forming collections of considerable extent. A 

 large number of these spores were likewise to be seen, detached from 

 their original adhesions, freely floating in the water, or collected in masses, 

 upon the peripheries of the small air-bubbles that had here and there 

 become entangled between the slide and the covering glass. In this latter 

 instance the spores exhibited a thicker and more opaque bounding wall, 

 and manifested, as in the case of lycopodium powder, the power of resisting 

 for some time the hydrostatic or wetting action of the water ; this property 

 had already been suspected by Professor Tyndall to be possessed by 

 these minute bodies, but had not previously been practically demonstrated. 



The hay within from four to six hours after maceration revealed, on 

 examination of a small fragment, a considerable alteration in the character 

 and comportment of the associated spores. Hitherto these had displayed 

 no signs of motion, a uniform stillness reigning throughout the entire 

 expanse of the microscopic field. Now, however, among the numbers that 

 had become detached from their original adhesion to the vegetable matter, 

 the majority exhibited an active vibratory motion that at first sight was 

 scarcely to be distinguished from the characteristic " Brownian movements." 

 The size of these motile spores corresponded with that of the quiescent 

 ones, not exceeding the i -20,000th of an inch in diameter, and without 

 recourse to the highest magnifying power and the most careful adjust- 

 ment of the illumination, it was not found possible to ascertain by what 

 means their locomotion was accomplished. Examined successively with 

 the tV, ^V. and 5V inch objectives of Messrs. Powell and Lealand, it was 

 at length satisfactorily determined that each individual spore or body was 

 furnished with a single, long, slender, whip-like organ or flagellum, whose 

 active vibrations propelled the spherical body through the water. These 

 minute motile corpuscles exhibited, in fact, at this early stage of their 

 development a type of organization in all ways comparable with that of the 

 simply uniflagellate genus Monas. 



A highly characteristic feature of these moving spores remains to be 

 mentioned. Although vast numbers of them were to be seen careering 

 singly through the water, a very considerable proportion were united to 

 each other in irregular clusters consisting of from two or three to as many 

 as a dozen, or, as still more generally occurred, from two to as many as 

 eight of them were joined laterally, so as to form floating moniliform or 

 necklace-like aggregations corresponding in general aspect and mode of 

 attachment with the normal moniliform colonies of the collared flagellate 

 type Desniarella moniliformis, hereafter figured and described. If watched 

 for a sufficient time, these clustered and serial aggregations were observed 

 to become disintegrated, each separate corpuscle thenceforward maintain- 

 ing an independent existence. In consequence of the characteristic aggre- 

 gate forms primarily exhibited by this special species, it has been further 

 found possible to definitely identify it with one of the types of animal- 

 cules described by O. F. Miiller in the year 1786, and upon which he 



