1893.] NEW-YORK MICROSCOPICAL SOCIETY. 101 



but what struck me with most interest durin'g a portion of the time 

 was the presence of beautiful vorlicellae in the sediment at the 

 bottom angles of the bottle. Above the sediment there appeared 

 to be a silvery cloud of monad-like infusoria; and while viewing 

 the vorticellse with a powerful compound hand lens, the bottle 

 being vertical, I observed that the coronal cilia of the vorticellae, 

 when expanded and revolving, produced a sort of whirlpool, into 

 which poured a funnel-shaped stream of the minute infusoria. 

 The vorticellae were attached to debris, and were constantly whirl- 

 ing their cilia and retracting their soft, elongated body. The 

 exuviae of dying infusoria or bacteria, even from the first day 

 of securing the brackish-water specimens, were rapidly covering 

 everything with a flocculent, ochreous pellicle, which accumulated 

 so rapidly that on the fifth day all the vorticellce were dead. 



The cause of motion in the Diatomaceae has eluded, so far, a 

 direct and positive solution, and the endosmotic and exosmotic 

 theory seems to be the most favorable hypothesis in the case. 

 The idea of exosmose and endosmose action would occur spon- 

 taneously to any one studying the biological functions of the 

 diatom. That there is, and can be, endosmotic action is demon- 

 strated by mounting the dried frustules with thin balsam. The 

 larger Pmnularice. of the Mobile Bay brackish source have the 

 major part of the air within the frustules replaced in a few min- 

 utes with the balsim; and this action of displacement of air 

 continues for days after the slide is prepared. This is proved by 

 the so-called canaliculi showing very clearly aid distinctly the 

 rib-like markings filled with air bubbles (That these spaces 

 are not canaliculi, but rather corrugations or flutings, I will 

 endeavor to sustain when I reach the subject of my experiments 

 in charging the markings of the diatoms with coloring matter.) 

 Gradually, after days, there is a full and complete expulsion of 

 all air from the frustules, provided the balsam is thin when first 

 used. If the balsam is quite thick, and dries readily, the air 

 will remain permanently. 



In regard to the substances designated as endochrome, chloro- 

 phyll, and a substance, derived from the chlorophyllaceous matter 

 of the diatom, known as phycozantina, I have thought it proper 

 to suggest that the contents of diatoms are not identical with 

 the chlorophyll of the desmids or of the leaves of plants, but 



