236 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
disappears as ripening is approached ; and this suggests the theory that 
the other acids are formed synthetically from oxalic and succinic acids. 
No starch was detected at any stage in the fruit itself. After various 
analyses and a comparison of the absorption spectra, the author states 
that the colouring matters of black and red currants are closely allied 
if not identical. 
Nitrification.* * * § — Herr J. Wortmann sums up the results of the recent 
researches on this subject of Sclilosing and Miiutz, Frank, Adametz, 
Warington, Frankland, Winogradsky, and others. He states that 
Winogradsky’s observations have had, as one of their results, to over- 
throw at a blow one of the generally accepted theories of vegetable 
physiology, that it is only the chlorophyll-containing cells that are able 
to assimilate carbon dioxide. 
■y. General. 
Vegetable Perfumes.t — Hr. M. Buchner describes the method of 
obtaining the fragrant vegetable essential oils in exhausted vessels at the 
ordinary or at very low temperatures. He states that the most of these 
oils consist either of terpenes with the formula C 10 H 16 , or of polyter- 
penes with the formula (GhHg)*. 
Fructification of Bennettites.J — Herr Graf zu Solms-Laubach has 
made a careful examination of the fructification of the fossil Bennettites 
Gibsonianas from the Isle of Wight. He has come to the conclusion 
that all the Jurassic and Neocomian stems which are termed Cycas- 
stems, so far as anything is known of their structure, belong to Bennet- 
tites rather than to the genuine Cycadese. He regards the Bennettitere 
and the Cycadete as co-ordinate groups, with probably a close relation- 
ship to one another, but probably both derived from a common stock, 
and not one from the other. The author is further of the opinion that 
Saporta’s class of Proangiosperms cannot represent a well-defined group 
in the genetic system, but must consist of members of different analogous 
developmental series, which have undergone evolution of a similar kind. 
B. CRYPTOGAMIA. 
Cryptogamia Vascularia. 
Antherozoids of Cryptogams, § — M. W. Beliajeff has come to a 
somewhat different conclusion from that of Guignard || with regard to the 
origin of the antherozoid in Muscineae, Characeae, and Vascular Crypto- 
gams. His observations were made chiefly on Filices and Characeae. 
In Filices he finds that the body of the antherozoid is composed of 
a distinct chromatic filament, and of an achromatic ground-substance ; 
and that the two extremities of the antherozoid do not contain chromatin. 
The anterior portion, and probably the entire achromatic substance of 
* Landwirthsch. Jahrb., xx. (1891) pp. 175-84. SeeBot. Centralbl., 1891, Beih., 
p. 476. Cf. this Journal, 1891, pp. 83, 680. 
+ MT. Naturw. Ver. Steierinark, 1891, pp. lxiv.-lxxi. 
j Bot. Ztg., xlviii. (1890) pp. 789-98, 805-16,821-33, 843-6 (2 pis.), and Ann. of 
Bot., v. (1891) pp. 419-54 (2 pis.). 
§ Scripta Bot. Hort. Petropol., iii. (1891) p. 104. See Malpighia, v. (1891) 
p. 229. Cf. this Journal, 1889, p. 785. y Cf. this Journal, 1889, p. 552. 
