TRANSACTIONS OF THE SECTIONS. 123 



drops, which seemed to be absorbed into the spores. As soon as this has occurred, 

 each green spore-globule, previously naked, becomes covered v^rith a clear glassy 

 membrane, its colour changes to red, and other coverings ai-e formed successively 

 within the outer one. Finally, the red spore-globule is enclosed in a peculiar stellate 

 wall. 



In another Conferva belonging to the genus CEdogonium, a singular mode of 

 fecundation has also been observed by Dr. Cohn. The ciliated "macrogonidia " of 

 this Conferva have long been known : this germinates into a long cellular thread. 

 The other sexual element of this plant consists of the so-called " resting-spores," 

 which are red globular bodies enclosed by a thick wall. But Dr. Cohn has observed 

 that the " microgonidia," which were detected by Alexander Braun, undergo a sort 

 of germination, and by this produce two small agile spermatozoa, which penetrate 

 the sporangium cells through a small aperture (which had been seen by Pringsheim), 

 and adhering to the spore, thus probably effect fecundation. 



The principal difference between the propagation of CEdogonium and that of Vau- 

 cheria and Spharoplea consists in this, that while in the two latter the fecundating 

 corpuscles (spermatozoa) are directly produced, and the male and female organs are 

 united in one confervoid individual, in the CEdogonium the moving: bodies are to be 

 regarded rather as gonidia, which are destined to germinate hke the great gonidia. 

 But from the microgonidia there issue the minute male individuals, consisting each 

 of a small cell, of which the whole contents are changed into spermatozoa. The 

 great gonidia (macrogonidia) germinate into large plants, consisting of numerous 

 long cells and generating the resting-spores. 



The observations of Braun and Pringsheim already show that similar phsenomena 

 must occur in others of the Confervee; and, according to Dr. Cohn, it seems very 

 probable that the fact of sexuality, although at present proved only of a few genera 

 of the Confervae, will very soon be discovered in all other kinds ; and that an act of 

 fecundation will be shown to occur in the simplest unicellular plants. In various 

 plants, one or other of the reproductive elements have been discovered singly, as in 

 ChcBto2}hora and Hydrodictyon ; but already enough is known to point to the desti- 

 nation of these bodies 



Dr. Cohn indicated the probable future progress of inquiry in respect to these 

 functions also in the Volvocinece, Floridese, Zygnemese, Desmidiese, and Diatomacese. 

 From these considerations the author drew the general conclusion, that sexual 

 difference and an act of impregnation are the necessary conditions of reproduction of 

 all plants from the highest to the lowest, and he regards it as probable that the 

 same will ultimately be proved of the lowest or infusorial animals. 



An attempt to solve some of the Difficulties of the Berhleyan Controversy hy 

 well-ascertained Physiological and Psychological Facts. By Richard 

 Fowler, M.D., F.R.S. 



The Berkleyans contend that we have no knowledge of matter but by gratuitous 

 inference from subjective sensation ; that, in reality, the mind has no direct per- 

 ception of anything but of impressions, conceptions or ideas. 



The generality of mankind, however, instinctively believe that impressions on our 

 organs of sense, like impressions on wax by a seal, are made by objects external to 

 the mind : such objects ^re supposed to be modifications of matter. It therefore 

 becomes necessary to ascertain what matter may really be. Berkley said there was 

 no matter ; and it was wittily replied, " It is no matter what Berkley said." In 

 our conceptions we have all the forms and colours and dimensions of matter, but 

 they are wanting in the impenetrability assigned to matter, and in the periodicity by 

 which some of its phsenoraena are noticeable — as the revolution of the planets, ad- 

 mitting of mathematical calculation, while our conceptions are fleeting, uncertain 

 and evanescent,— come when they are least expected, and, in emotions, particularly 

 fear and remorse, resist all the efforts of volition to exorcise them. 



The question then recurs, what is matter ? Its impenetrability has been supposed 

 to consist in a nucleus surrounded by spheres of attraction and repulsion. But as 

 it is useless to assign more causes of the fact than are necessary to produce it, phi- 

 losophers, Newton, Boscovich, Priestley and others, have, the author thinks, expert- 



