1882.] 



MICROSCOPICAL JOURNAL. 



21T 



that they indicate that the form and 

 structure of organized cells may not 

 entirely depend upon the life-force 

 within them, but may be also influ- 

 enced by the forces of molecular phy- 

 sics with which we are familiar. In 

 other words, it may be said that a 

 typical cell is spherical because the 

 natural tendency of matter is to 

 aggregate into spherical masses, and 

 not because the forces of life tend 

 to give it that shape — which we know 

 from observation is not the case. 



The Vitality of Germs. — A note 

 ont his subject by A. Certes, in the 

 Bulletin de la Socie'te Zoologtque re- 

 counts an interesting experiment car- 

 ried out by the author. In March, 1878, 

 he received from Algeria some salt 

 water containing algae, infusoria, and 

 some larvse. This was allowed to 

 evaporate in the sun and the sediment 

 was carefully collected and kept three 

 years — until April, 1881 The sedi- 

 ment was then placed in boiled and 

 filtered rain-water, and care was 

 taken to exclude germs. Ciliated 

 infusoria and flagellates soon ap- 

 peared, and about the beginning of 

 June there were found some larvae, 

 at first microscopic. They multiplied 

 and increased in size and soon trans- 

 formed into an animalcule of about 

 one centimetre in length, which was 

 recognized as Artemia salina. 



The Sahel of Algeria is overlooked 

 by a small mountain, the Boudzarea, 

 on the summit of which remain the 

 trenches of an old Turkish fort. 

 In 1877 the drouth was excessive. 

 After the first rains the author climbed 

 the mountain and, in the same trench 

 where he had found it eight months 

 before, he found an abundance of 

 Blepharisma lateritia, a ciliated in- 

 fusorium. It had, either as an animal- 

 cule or as germs or cysts, withstood a 

 torrid heat for several months. 



The Infusoria. — The sixth and 

 last part of the " Manual of the In- 

 fusoria" by Mr. W. Saville Kent has 

 been issued, and as the work is now 



complete we take pleasure in congra- 

 tulating both author and publisher. 



The "Manual of the Infusoria"" 

 will be an enduring monument to the 

 ability and persistent lajjor of its 

 illustrious author. In the few brief 

 notices we have given from time to 

 time, we have not presumed to review 

 any portion of it, and now that it is 

 complete we can only express our 

 sincere appreciation of its value as a 

 standard work on the infusoria, and 

 also of the scientific methods of in- 

 vestigation and research which 

 throughout have characterized the 

 observations of the author. 



It would be remarkable if no errors 

 of interpretation have crept into such 

 a large and comprehensive work. 

 But such as there are can only be 

 eliminated by the results of future 

 study. Probably the author's views 

 concerning the animal nature of the 

 Myxomycetes will be regarded by 

 most readers as erroneous, and the 

 argument in the admirable chapter 

 designed to prove the protozoic na- 

 ture of sponges will not be univer- 

 sally accepted by the followers of 

 Hackel; although they seem convinc- 

 ing enough. However, we have no 

 words of presumptuous criticism to 

 offer here. For more than twenty 

 years Pritchard's great work on the 

 Infusoria has been essential to the 

 student of minute forms of life. 

 When Pritchard wrote, almost 

 nothing was known of the life- 

 histories of the organisms he de- 

 scribed. Mr. Kent has availed him- 

 self of the vast stores of knowledge 

 which have accumulated during that 

 long period, to which he has con- 

 tributed a goodly share himself. His 

 classification is, therefore, a great im- 

 provement upon earlier ones, and 

 perhaps it is as good as our present 

 knowledge renders possible. 

 o 



Trichina Spiralis. — P. M^gnin 

 has contributed an article to the So- 

 ci^t6 Zoologique de France on *' Min- 

 ute Agamous Encysted Helminthes 

 which may be confounded with 



