212 NATURAL SCIENCE. March, 



such as the possession of nucleoles by the former and not by the 

 latter. 



The act of fertihsation or fecundation appears to consist in the 

 actual fusion of the nuclei of the male and female cells; at least this 

 is the view taken by one of the highest authorities on this subject — 

 M. Guignard — from a very careful series of observations on Lilium 

 martagon and Fritillaria imperialis, in opposition to the theory of Van 

 Beneden and some other observers. This fusion is assisted by the 

 action of remarkable bodies which have only recently come under 

 observation, and which have been termed " tinoleucites " or " direct- 

 ing spheres." These bodies, which have been observed by Guignard 

 and Van Tieghem in plants, and by Fol and others in animals, are 

 minute spherical masses of protoplasm occurring in both the male 

 and female cells, which appear to exercise the function of directing 

 the course of the male nucleus so as to bring it into contact with the 

 female element. There appears to be also some directing principle 

 in the higher Cryptogams which governs the antherozoids in finding 

 their way to the oosphere within the archegone. 



Without dogmatising on so intricate a question, the theory may 

 at least be hazarded that every act of fertilisation is simply a modifi- 

 cation of a process of nutrition, the conveying to a potential germ of 

 some property which it does not derive from its own ancestors, but 

 which gives it greater completeness, and endows it with greater 

 resources in the struggle for existence. Sufficient, at all events, 

 has been said to show how rich a field there is still open to the 

 skilled microscopist in the investigation of the interesting problems 

 connected with the perpetuation of animal and vegetable life on 

 the surface of the globe. While it is probable that no human 

 researches will ever lead to a solution of the questions : " What is 

 life ? " and " How were the phenomena of life first infused into 

 inorganic matter ? ", we seem, year by year, to be able more closely 

 to follow the steps by which, from the first germs of life, has been 

 gradually evolved that marvellous complexity in the animal and 

 vegetable worlds, the laws of which excite our increasing wonder 

 and admiration the more minutely we investigate them. 



BIBLIOGRAPHY FOR 1889-92. 



Alfken and Verhaeff (insular floras), Ahhandl. Natww. Verein Bremen, 1891, 

 pp. 65 and 97 ; Arcangeli, Beccari, Caleri, Delpino, Martelli, and Vinassa (various 

 papers on the fertilisation of Araceae), Nuov. Giorn. Bot. Hal., Malpighia, Atti. Soc. 

 Tosc. Sci. Nat., and Bull. Soc. Toscana Orticoltura ; Ascherson (Cyclamen), Ber. 

 Deutscli. Bot. Gesell., 1892, p. 226 ; Beach (hybridisation of vine), Bot. Gazette, 1892, 

 p. 282; Beketow (Umbelliferse), Bot. Centralblatt, vol. xlv., 1891, p. 381 ; BelajieflF 

 (Gymnosperms), Ber. Deutscli. Bot. Gesell., 1891, p. 280; Belajieff (Cryptogams), 

 Scripta Bot. Hort. Petropolitana, iii., 1891, p. 104 ; Bottini (Hydromystria), Mal- 

 pighia, 1891, p. 340; Brandza (anatomical character of hybrids), Bonnier's Rev. 

 Gen.de Bot., 1890, p. 433 ; Burck (various papers on cross- and self- fertilisation), 

 Ann. Jard. Bot. Buitenzorg, 1890-91, and Bot. Zeitung, 1892, p. 121 ; Carter (pollina- 

 tion), Bot. Gazette, 1892, pp. 19 and 40 ; Caruel (function of insects), Bull. Soc. Bot. 

 Ital., 1892, p. 108 ; Chauveaud (impregnation of several embryos), Comptes Rendus, 



