212 NATURAL SCIENCE. Marcu, 
such as the possession of nucleoles by the former and not by the 
latter. 
The act of fertilisation 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 Fritillavia 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), Abhandl. Naturw. Verein Bremen, 1891, 
pp. 65 and 97; Arcangeli, Beccari, Caleri, Delpino, Martelli, and Vinassa (various 
papers on the fertilisation of Aracez), Nuov. Giorn. Bot. Ital., Malpighia, Atti. Soc. 
Tosc. Sci. Nat., and Bull. Soc. Toscana Orticoltuva; Ascherson (Cyclamen), Ber. 
Deutsch. Bot. Gesell., 1892,’ p. 226; Beach (hybridisation of vine), Bot. Gazette, 1892, 
p. 282; Beketow (Umbelliferze), Bot. Centralblatt, vol. xlv., 1891, p. 381; Belajieft 
(Gymnosperms), Ber. Deutsch. 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. Fard. 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, 
