MIOfiOHYDRA RYDEKI. 629 



this long period, I had entirely failed to see the act of feeding 

 until the last days of the last surviving mature individual. 



I copy from my note-book, under date of May 11th, 1885 : — 

 "On this date, for the first time, I saw M. ryderi capture 

 and swallow a small rotifer. A hydroid standing upon the 

 clear surface of my glass dish had developed a lateral branch, 

 which had only recently completed its capitulum. While 

 watching the branch this evening, one of the turtle-back 

 rotifers, that have been so plentiful, came swimming by and, 

 fortunately for me, touched some of the palpocils, when it 

 immediately lost all power of motion, and adhered, or was 

 held, to the surface of the capitulum. This extremity was 

 then deliberately curved around in a direction toward the 

 rotifer, pressing and holding it against the adjacent body of 

 the hydroid, when, by some method not clearly discovered, 

 its head was directed toward and absorbed into the ex- 

 panded oral aperture of the latter. Its downward progress 

 was then relatively quite rapid, so that it was little more than 

 five minutes from the moment of capture before the caudal 

 appendage of the victim had passed into the orifice, and the 

 whole creature could then be followed through the channel 

 of nearly transparent cells to its resting place about the 

 centre of the polyp. The so-called gizzard-motion of the 

 rotifer still suggested life; but Microhydra's digestion must 

 have been quite energetic, for about an hour later the empty 

 test had already been ejected. 



" About the same time I witnessed the act of ejection of 

 the test of a similar I'otifer from the main extremity of this 

 hydroid, and the next evening I counted six of such ' relics 

 of mortality ' surrounding this form of voracious simplicity." 



Two modes of reproduction or development were noticed.^ 

 The most important of them, perhaps unique in its character, 

 was seen in the formation of asexual larvas non-ciliated and 

 inert (represented in diagram fig. 21), which, after one or 

 two weeks, became fixed upon their pedal discs, developed 

 capitul^, and appeared essentially mature (fig. 24). 



' This was twelve years before tlie medusa was discovered. 



VOL. 50, PART 4. NEW SERIES. 45 



