RECENT MEMOIRS ON FRESHWATER RHIZOPODA. 117 



ing blackish, and the anastomoses remaining — still they lost 

 the resistance of life, floating aimlessly in the water, hanging 

 around the colony like hairs. The application of iodine 

 gave far more unfavorable results. 



The author notes that the food captured by this rhizopod 

 is mostly such as is already undergoing decay ; rarely do 

 thejr incept living organisms, but on one occasion he saw 

 a Vorticella captured, and at another some alga-spores. To 

 myself this form appears not to be at all a " hungry " one. 



The author's attention was largely directed to the gaining 

 a knowledge of the development of this form. Hertwig 

 first refers to the long-since expressed views founded on the 

 observations of Carter, Wallich, and Greeff, especially of the 

 latter in his Amoeba terricola, where the so-called nucleus 

 was supposed to be a reproductive organ, which by a break- 

 ing up into a number of solid, sharply bounded bodies, and 

 escape of these into the general parenchyma of the body, and 

 in some way combining with certain spermatozoa-like bodies 

 already there, gave rise to so many germs. Carter, on the 

 other hand, formerly supposed that the nucleus gave rise to 

 spermatozoids, whilst the ovula were formed in the surround- 

 ing protoplasm ; afterwards, as regards DiJJlugia pyriformis, 

 coming more to the views of Greeff, regarding the sexual 

 character of the reproduction as expressed in the " conjuga- 

 tion," a view foreshadowed by Claparede and Lachmann, who 

 regarded the nucleus as a "glande sexuelle." 



Bearing these views in mind, the author applied himself 

 especially to a study of the nucleus in this form to see if any 

 evidence should be afforded, demonstrative of its sexual 

 significance; and he believes he has come to the certain 

 result that neither in the formation of new colonies nor in 

 the progress of growth does any process take place other 

 than simple cell-division, in unison with the lowliness of the 

 whole group as simple unicellular organisms. 



To arrive however, at any conclusion it was requisite to 

 discover (1) the mode in which new colonies are produced, 

 and (2) the mode of growth of a colony already begun. 



In regard to the former question the author, confirming 

 my own record of two nucleated bodies within a single parent 

 test, carries the observation a great deal farther. In a number 

 of individuals of a colony so subdivided into two, he found 

 that one of these portions became changed into a zoospore, 

 which swarmed away from the colony independently. On 

 one occasion he noticed certain individuals containing two 

 nuclei, but without having witnessed the act of subdivision 

 into the two daughter individuals. 



