1880.] 



MICEOSCOPICAL JOURJS'AL. 



15 



istic form ; the other much larger, 

 generally club-shaped, representing 

 a kind of pocket, or elongated cap- 

 sule, nearly at right angles to the 

 principal filament, and having the 

 same green color, 



I oj)ened one of these, and saw 

 the parasite gradually disengage 

 itself from the green matter. It 

 was a blackish and extremely soft 

 body, continually contracting and 

 modifying its shape." 



The parasitic cysts, in which the 

 animal developes, are only the per- 

 sistent branches which bore the 

 reproductive organs, greatly in- 

 creased in size. The animal lays 

 its eggs within the capsule and 

 then dies ; the eggs hatch in ten 

 or fifteen days, when the young 

 rotifers make their exit into the 

 surrounding water, through open- 

 ings in the walls of the plant. 

 They soon return to the plant 

 through openings, just as they left 

 it, dejDOsit their eggs, and die. iV. 

 parasitica and iv . Petromyzon are 

 two other species of this genus, 

 which are said to inhabit the 

 spheres of Volvox glohator. 



A recent contribution of Professor 

 Karl Mobius, bids fair to keep alive 

 the discussion about the animal ori- 

 gin of Eozoon Canadense, for a con- 

 siderable time to come. The j)aper 

 is abstracted and extensively illus- 

 trated, in two numbers of Natxire. 

 We cannot do justice to the views 

 of Professor Mobius by any ab- 

 stract in the short space at our dis- 

 posal ; but we may say, that he 

 has evidently devoted much time 

 and labor to the study of the struc- 

 ture known as Eozoon^ and he has 

 reached the conclusion that the 

 Eozoon structure is not of animal 

 origin. Both Dr.W. B. Carpenter 

 and Principal Dawson have criti- 

 cised the work of Professor Mo- 

 bius, and none of his statements 

 seem to have altered the opinions 



of those able investigators. The 

 subject cannot be properly studied 

 without very careful preparation, 

 and intimate acquaintance with 

 foraminiferal structure. For this 

 reason, we consider that the most 

 competent authorities on this sub- 

 ject are Dr. Carpenter and Princi- 

 pal Dawson, and we still hold to 

 the belief in the animal origin of 

 Eozoon. 



We must add, however, that we 

 have long wished for a good view 

 of the structure that Dr. Carpenter 

 has described, but have not seen it 

 on any slide we have examined. 



A full and complete memoir on 

 the subject of Eozoon^ is in course 

 of preparation by Dr. Carpenter 

 and Prof. Dawson. 



We are obliged to leave untouched 

 many interesting subjects in the 

 "Review" this month, owing to the 

 space required for other matter. 



Catalogue of the Diatomaceae. 



The very valuable " Catalogue of 

 the Diatomacese," by Frederick 

 Habirshaw, of New York, has been 

 revised, enlarged and brought up 

 to date by the author, in the expec- 

 tation that it would be published 

 by Dr. J. Pelletan, editor of the 

 late Journal de Micrograjohie, 

 Paris, France. After, extensively 

 advertising the book in his journal, 

 and soliciting subscriptions for it, 

 both Dr. Pelletan and his journal 

 have mysteriously disappeared. In 

 concluding his " Review " in the 

 June number of the Journal de 

 Micrographie^ the learned Doctor 

 says farewell in a few graceful 

 sentences, telling his readers that 

 he intends to take a " vacation " 

 during the months of July and 

 August, and that he would not 

 issue his journal again until Sep- 

 tember or October ; at which time, 

 we doubt not, he expected to 



