Developmental History of Infusorial, Animal Life. 367 



To my mind this view scarcely admits of a doubt, and it is 

 clear that the young of the Amoeba in some manner find their 

 way into the cell, just as it is on the point of breaking up, and 

 so become developed in a situation where they are at once 

 provided with a due amount of nourishment for the support of 

 their earliest state of existence. I must not, however, omit to 

 say that no less an authority than Dr. Hicks still holds to the 

 former opinion, and fully believes, after many careful observa- 

 tions, that these bodies, which move freely about in the cell, 

 ever changing their position, protruding and retracting por- 

 tions of their membranous walls, exactly as the Amoeba do, 

 are really and positively what they appear to be, animals be- 

 longing to the class of Mhizopoda. He further observes, that 

 after the amoeboid bodies have begun to shift about in the 

 cell, for every such moving body there was a corresponding 

 empty space ; and he cannot suppose it possible that any 

 parasite could enter the cell from without, but that every 

 examination tends to confirm his opinion that the amoeboid 

 organism is really the product of the metamorphosis of a mass 

 of vegetable protoplasm. 



Another careful observer, Mr. Archer, of Dublin, has also 

 recorded, the development of amoeboid bodies in the cells of 

 Steplianosjphcera pluvialis ; he looks upon the phenomenon as 

 analogous to that which is known as occurring in one of the 

 stages of development of the Qregarinida, the encysting 

 stage ; the central nucleus and vesicle disappear, and after a 

 certain time "the mass breaks up into a series of rounded 

 portions, which become elongated and slightly pointed at each 

 end, constituting a little body which has been called a ' pseudo- 

 navicella/ from its striking resemblance to the Diatomaceous 

 navicula ; the capsule next bursts, and the pseudo-navicellge 

 are scattered, and pass out of the body of the creature which 

 they inhabited." * 



Dr. Hicks believes that he has seen the young volvox pass 

 into an amoeboid state ; in other words, the conversion of the 

 protoplasm of a vegetable cell into an animal. He says, 

 " Towards the end of the autumn the endochrome mass of the 

 volvox increases to nearly double its ordinary size, but instead 

 of undergoing the usual subdivision, so as to produce a macro- 

 gonidnim, it loses its colour and regularity of form, and becomes 

 an irregular mass of colourless protoplasm, containing a number 

 of brownish granules. >} f 



* Huxley. 



t I have continuously had the volvox under the microscope during the past 

 Summer and autumn, and made more than a hundred examinations without having 

 once seen anything approaching to the form of an Amoeba in the interior of the 

 cell. 



