66 Miscellaneom. 



fact, that whilst the Ozothallia and the Fucus serratus are very con- 

 stant in form, the F. vesiculosus is extremely polymorphous. 



In the higher Cryptogamia the phaenomenon of fecundation pre- 

 sents two principal modifications. In the Mosses and Characese it 

 takes place in adult plants, and appears to be necessary for the for- 

 mation of the reproductive bodies ; it must consequently be repeated 

 every time that the plant fructifies, and in this respect approaches 

 the process in the phanerogamous plants. In the Equisetacese, the 

 Ferns, the Lycopodiacese, and the Rhizocarpese, fecundation takes 

 place some time after the germination of the spore ; its result is the 

 development of the frond which will fructify every year without fresh 

 fecundation. The Fucacese present a third modification of the phae- 

 nomenon, which resembles the second rather than the first, and which 

 has perhaps still more analogy with what takes place in the case of 

 animals. Here it is upon the spore itself that the fecundating action 

 of the antherozoids is exerted, and it is only in consequence of this 

 contact that the spore is developed into a frond capable of fructifying 

 every year without fresh fecundation. — Comptes Rendus, April 25, 

 1853. 



TIME OF SPAWNING OF BRITISH CRUSTACEA. 



To the Editors of the Annals of Natural History. 



Weymouth, June 18, 1853. 



Gentlemen, — I enclose you an addition to my list of the " Time 

 of Spawning of British Crustacea " which appeared in the * Annals 

 of Nat. Hist.' vol. viii. p. 501. 



I wish to draw the attention of your readers to an error in that 

 paper, in which Crangon bispinosus is enumerated instead of Crangon 

 trispinosus. I have not yet been able to obtain C. bispinosus. I am 

 at a loss to conceive how this error could have occurred, as my notes 

 are correct. 



I have now succeeded in fixing the dates of carrying spawn of 

 thirty-eight species of British Crustacea, and I have myself obtained 

 at this place fifty-four species, and fully expect to add to that 

 number. 

 ■ Amongst my latest captures are Crangon spinosns, Hippolyte 

 Whitei (mihi), My sis chameleon. My sis GriffithsicB, and one or two 

 species I cannot at present make out. 



My dredger is a very clever fellow, and would be pleased to supply 

 anything he might obtain when dredging. 



I am. Gentlemen, yours obediently, 



William Thompson. 



Species. Date when fonnd General Remarks, 



carrying ova. 



Achctus Cranchii Aug. 18, 1852. I dredged two in six fathoms, 



shingle and weedy bottom : one 

 female had two single ova; 

 they are of a deepish yellow 

 colour. 



