38 phoceedtxos of the 



principles of biology which have fallen within the limits of the 

 past year. 



Prof. Moseley's lecture before the British Association is full 

 of interesting facts which serve to thi'ow much new light upon 

 the procet^ses of organic evolution ; and the same remark applies, 

 though in a lesser degree, to Prof. Forel's paper on Pelagic 

 Fauna; of Freshwater Lakes (Centralbl. ii. 299-305). 



The curious question of Symbiosis continues to be discussed. 

 Prof. Lankestcr opposes the views of Brandt and Semper that the 

 green corpuscles in the cells of SpongiUa jluviaiilis and Hydra 

 viridis are parasitic unicellular alga^, but accepts their views on 

 this point (with some reservation) so far as the yellow cells of 

 Anthozoa and Eadiolarians are concerned (Quart. Journ. Micro. 

 Sc. xxii. 229-2.5-t). It is evident that an important field of 

 inquiry is opened up, should it be definitely proved that the 

 gi'een coloui'ing-matter in question is due, as Lankester believes, 

 to the presence of chlorophyll. Later in the year, 0. Hamann 

 published a paper supporting the view of symbiosis (Zeitschr. 

 f. wiss. Zool. xxxvii. 457-461), to which Lankester has replied in 

 'Nature' (xxvii. 87-8). 



Metschnikoif has published a paper (Zool. Anzeig. v. 310-316) 

 describing certain physiological jjrocesses which he has observed 

 to take place under suitable experimental conditions in the endo- 

 dermnl cells of a hydroid parasite, and which he deems himself 

 justified in regarding as processes of intracellular digestion. 

 He also argues that similar processes are in all probability the 

 general rule among Turbellaria and Ccelenterata. This is clearly 

 a most promising field for further inquiry. 



Finally, allusion may be made to the curious experiments which 

 were first made by Fouruier in 1878, and have been repeated 

 during the past year by Monnier, Vogt, and Yolin (Coinpt. 

 Kend.). These experiments consist in the production of so- 

 called " mineral organisms," or of structures artificially manu- 

 factured out of inorganic substances which not only present the 

 morphological appearance of organic structures, but even strangely 

 imitate the physiological processes of growth, repair, the for- 

 mation of cells, and protrusion of pseudopodia. It would certainly 

 be premature to express a hope that these interesting researches 

 are destined to throw any light upon the formation of living 

 out of non-living material ; but we ini:y at least saj that they 

 are the most promising researches in this direction which have 

 hitherto been made, seeing that they refer to the almost un- 

 explored department of chemistry which deals with colloids — 

 out of which life must have arisen if it has been evolved, and 

 that they have at any rate been successful in breaking down one 

 of the cliicf distinctions between organism and auorganism ; for, in 

 the words of Dr. Volin's paper, " we can no longer say that only 

 living things grow, unless we reckon these as living." 



