STRUCTURE.] VIEWS OF GRIFFITH. OF VALENTINE. 109 



the organs of reproduction of Urn-Mosses cannot be com- 

 pared strictly to the parts of fertilisation of perfect plants. 

 I must not, however, omit the opinion of other botanists upon 

 this subject. The office of males has been supposed by 

 Micheli to be performed by the paraphyses; by Linnaeus 

 and Dillenius, by the sporangia; by Palisot de Beauvois, by 

 the sporules ; by Hill, by the peristomium ; by Koelreuter, by 

 the calyptra ; by Gaertner, by the operculum ; and, finally, 

 Hedwig has supposed the males to be the antheridia. The 

 female organs were thought by Dillenius and Linnaeus to be 

 assemblages of antheridia; by Micheli and Hedwig, the 

 young sporangia ; and, by Palisot de Beauvois, the columella. 

 Mr. Griffith thought that the sexuality of Urn-mosses was 

 established by a breaking up of the tissue terminating and 

 closing the style (subsequently to the application of a parti- 

 cular matter,) whereby the style becomes a canal opening 

 exteriorly; by the browning observable in the orifice of 

 this canal extending downwards until it reaches the cavity, 

 &c. But it seems to me that the observations of Mr. Valen- 

 tine dispose of the question conclusively, until some further 

 evidence shall have been produced. 



" The most satisfactory refutation of the theory of Hedwig 

 will be found in the anatomy of the pistillum, where the im- 

 pregnation of the seeds is supposed by him to take place. 

 It is strange that the structure of this organ should have 

 been so long misunderstood ; that the young theca, under 

 the name of germen, should have been supposed to be con- 

 cealed in the bosom of the pistillum ; a supposition of which 

 there is not the shadow of a proof. If we refer to the 

 description in the first part of this paper, we shall find that the 

 cavity of the pistillum is occupied, in the first instance, by a 

 single cell ; and that this cell always remains at the base of 

 the seta, where it may be found to the very last, tipping the 

 conical extremity. We also find that before one particle of 

 the theca can be formed, the seta must be developed; a 

 process which, in many instances, occupies two or three 



" They soon became jointed, from the addition of fresh cells at the extremities. 

 They then began to branch, and after a time produced leaves." ( Valentine in 

 Linn. Trans, vol. xvii.) 



