ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 685 



Ehodomelacefe, Corallinacefe, Fucaceee, Dictyotea3, Scytosiphonaceae, 

 Ulvaceee, Confervaceae, Valoniaceae, Bryopsidese, Codiacese, Dasycla- 

 daceae, and Nostocaceae. 



Rabenhorst's Cryptogamic Flora of Germany (Marine Algae). 



— We have now the comi)letion of this, which constitutes the second 

 volume of the entire work. The last two parts (9 and 10) include 

 the completion of the genus Cladophora, and the families Anadyo- 

 .menefe, ValonieaB, Dasycladeje, Nostocaceae, and Cbroococcacefe, in- 

 cluding under the Nostocaceae the genera Rlvularia, Lynghya, 

 Oscillaria, and others. The mode in which this section of Dr. 

 Eabenhorst's great work has been accomplished reflects the greatest 

 credit on Dr. F. Hauck, to whom it has been intrusted. 



Diatoms and Bladderwort.* — Mr. H. Taylor has forwarded to 

 * Science Gossip ' a slide containing a bladder of Utricularia upon or 

 within which are to be seen numerous frustules of diatoms, upon the 

 decomposing endochrome of which he thinks the plant may have fed. 



He says that Mr. Darwin, who does not, in his work on carni- 

 vorous plants, mention Diatomaceae being found in the bladders of 

 any of the species, " appears to think the taking-in of food by the 

 bladders is not owing to any voluntary act on their part, but that the 

 different things found in them have merely forced their way in ; but 

 as many of these diatoms are stipitate and attached forms, having 

 no power of locomotion, like the free frustules, this looks very much 

 like their being seized by the antennas round the valve of the blad- 

 der, and conveyed or swallowed in." Mr. Taylor is not, however, 

 certain whether the diatoms are inside or outside the bladder, and 

 even if they be inside it still remains to be shown that they are 

 utilized as food by the plant. 



Mr. F. Kitton has given his opinion as to the position of the 

 diatoms. Speaking about the slide forwarded, Mr. Kitton says : 

 " The diatoms are, I have no doubt, upon the bladder of the Utricu- 

 laria as the species are all parasitic (and no doubt occurred on other 

 parts of the plant) ; they could not have been injected by the bladder, 

 as it possesses no prehensile organs which would be necessary to 

 detach the diatoms from their stipes. The following are the species 

 attached : Gomphonema constrictum, Synedra cajntata, Cocconema lan- 

 ceolatum, Diatome vuhjare." The point, however, is one of some 

 interest, and it would bo well if it were thoroughly cleared up by 

 means of the examination of fresh specimens, Mr. Taylor's having 

 been a dried one. 



Structure of the Cell-wall of Diatoms.f — Dr. 0. MUller replies to 

 the paper by Dr. J. H. L. Flogel J which has appeared in this Journal. 



ilo states the difference between Dr. Flogel's view and his 

 own to be that the former considers he has jjrovcd the existence 

 within tho cell-wall of Plcurosigma of numerous closed cavities 

 corresponding to the well-known polygonal markings on tho surface ; 



* Sci. -Gossip, 1885, p. 104. 



t Ber. DeutBch. Hot. Gesoll., ii. (ISS.'J) pp. 487-91 (I fig.). 



i See thia Journal, iv. (1884) pp. 005-2;i, 6J5-aO (5 pl«.;. 



