OF SANTALUM ALBUM. 77 



strated to take place in some of the lower plants. I pass over the numerous discoveries 

 that have been made of late years in the higher Cryptogamia, from the Marsileacea to 

 the Liverworts, showing the pre-existence of a germ, and its fertilization by spermatozoids. 

 I may refer to my own jiubUcations on this subject elsewhere*. The cases most imme- 

 diately interesting to me in this instance are those described by Thuret in the Fucacece, 

 already repeated by Pringsheim, and the researches of the latter and of Cohn on certain 

 filamentous Coufervoids. According to the elaborate investigations of Thuret f the 

 spores of Fiicus are discharged from the spore-sacs as globules of protoplasmic substance, 

 bounded by the structure denominated by Von Mohl the primordial utricle, without a 

 cellulose coat. Wliile swimming free in the water, spermatozoids come in contact with 

 them in large numbers, and after a certain time a ceUulose coat is developed upon the 

 surface of the spore ; the latter thus becomes encysted, and forms a true eeU, wliich then 

 germinates, to produce a new plant. Pringsheim| describes essentially analogous pheno- 

 mena as occi.u'ring (inside the jiarent-ceUs) in Vaucheria, and Cohn's§ account of the 

 fecundation of the spores of Sphmroplea also agrees with these. 



These facts, together with those I have brought forward in this paper, tend to prove 

 that the process of impregnation in plants consists in the absolute admixture of the pro- 

 toplasmic substance of two cells ("male" and "female"); of which the female (or 

 germinal) substance or body always pre-exists in the form of a nucleus or " protoplast," 

 while the male (or spermatic) substance exists in the form of a granulose fluid. In the 

 Flowering Plants the spermatic fluid is conveyed directly into the embryo-sac by the 

 channel of the pollen- tube ; a similar process appears to exist in the conjugation of the 

 lower AlgcB ; in other cases the spermatic fluid is conveyed from organs situated at a 

 distance from the parent-cell of the germinal vesicle, by the agency of locomotive struc- 

 tures (spermatozoids) developed in the spermatic cells, bathed in and discharged with 

 their contents, and themselves composed of the nitrogenous protoplasmic matter of ceU- 

 contents. 



In my Memoir on Orchis Morio || , I described the nascent germinal vesicles as cells. 

 Hofmeister and others in like manner call them cells ; but comparison of my older draw- 

 ings and those of Hofmeister with new observations, leads me to believe that, on careful 

 examination, these bodies will be found to consist of nuclei or " protoplasts " before fertili- 

 zation^. I may note in reference to this, that I have already some confii-mation from 

 another case besides Santalum, and I trust to bring forward hereafter more complete 

 evidence on the sul)ject. 



Jan. 30, 1856. 



* Report of the British Association, 1851 ; Annals of Natural History, 2 ser. is. p. 441 ; Linnean Transactions, 

 xxi. p. 1 17. 



t Ann. des Sciences nat. 4 ' ser. ii. p. 197. + Bericht Berlin Akad. March 1855. 



§ Bericht Berlin Akad. May 1855. ]| Linn. Trans, xxi. p. 7. 



% Certain circumstances which I observed in the archeyonia of the Ferns, also afford good reasons for inquiring 

 whether the parent-cell of the germinal vesicle is not open at a certain period there, offering a passage for the 

 spermatozoids to a naked nucleus. See especially the figures 56, 57, 63-70 of plate 1 6 in my Memoir on the Deve- 

 lopment of Ferns (Linn. Trans, xxi. p. 117). 



