Ehrenberg on Infuswia from the South Pole, 169 



have in vain searched for such a structure as is represented in 

 the ' Algae Britannicse'; from a careful examination it appears that 

 the fructification of this species is essentially the same as that 

 which has been called acrospermal. It was remarked in a former 

 communication that Asperococcus presents the basisperms and 

 their accompanying simple filaments completely exposed; so of 

 Cutleria it may be probably legitimate to say, that its fructifica- 

 tion represents the acrospermal arrangement of a Fucus also 

 placed on the surface, without any inflexion of the frond to form 

 conceptacles. The accompanying figures represent the structure 

 of the fruit in the genus alluded to. In this genus the asci and 

 sporidia are exceedingly delicate and transparent : figs. 1, 2, 3 

 represent both ; fig. 4, one of the latter separated. 



XXII. — On Microscopic Life in the Ocean at the South Pole, and 

 at considerable depths* By Prof. Ehrenberg*. 



The following is the substance of a paper laid by Prof. Ehren- 

 berg, May 23rd, 1844, before the Berlin Academy, and contain- 

 ing some of the results derived from his recent investigations 

 upon materials furnished from the South Polar expedition of 

 Captain Ross and the voyages of Messrs. Darwin and Schayer ; 

 their object being to determine the relation of minute organic 

 life in the ocean, and at the greatest depths hitherto accessible. 

 Last year the author submitted to the Academy a survey of 

 the geographical distribution of such organisms over the entire 

 crust of the earth ; but the field of these inquiries being one of 

 such vast extent and importance, it became evident to him, that 

 to arrive at any positive general results, it was necessary to exa- 

 mine the subject under a more special point of view, and under 

 this conviction, two different courses of investigation suggested 

 themselves as best adapted to fulfill that purpose ; viz. first, to 

 * ascertain both the constant and periodical proportion which mi- 

 nute organisms bear to the surface of the ocean in different lati- 

 tudes; and secondly, to examine submarine soil or sea-bottom 

 raised from the greatest possible depths. It is an easy matter, 

 generally, to collect materials of this kind; but before applying 

 to them the test of philosophic criticism and research, the author 

 feels that it is essentially requisite to retrace the contributions of 

 other writers upon the same subject ; premising, however, that 

 their value will always be enhanced in so far as the materials col- 

 lected have been obtained with due care and reference to their 

 several localities. 



* From the Proceedings of the Berlin Academy for May, and communi- 

 cated by the Author. 



Ann. $ Mag. N. Hist. Fo/.xiv. N 



