374 
POPULAR SCIEXCE REVIEW. 
structure, so in function, there are three female organs ; for when all three 
receive the same pollen they are acted on differently ; and, conversely, the 
same holds good with the three sets of stamens. The experbnenter has 
also pointed out many other facts of the highest interest to physiological 
botanists, but for which we must refer our readers to his paper in the Journal 
of the Linnean Society, vol. VIII. p. 169. 
Varieties of Spermatozoids. — According to the conclusions arrived at by 
Schacht, in a monograph, published last year, there are present in the vege- 
table kingdom three distinct and typical forms of spermatozoids. {a) Those 
found among the Algce ; those of the Equisetacece ; and (c) those cha- 
racteristic of the Characece. There is furthermore a distinction in regard to 
the mode of development of these bodies. Thus in the Algce are found the 
simplest forms of reproductive organs and a direct germination. In the 
Equisetacean type, in which Herr Schacht includes the ferns, the organs 
become more complex, and are arranged upon a prothallium ; and if the 
Lycopodiacece and JRhizocarpece are conjoined with these families, there is ob- 
served the arrangement of the male and female apparatus upon the same 
surface or expansion. In the Characean type the spermatozoids, though 
similarly constructed, “ make their appearance on the fully-developed plant ; 
no direct germination ensues, but rather the production of a prothallium from 
a budding, out of which arises the j^oung plant.” — Vide abstract of Schacht’s 
memoir in Microscopical Journal, No. XVII. 
The External form of Sigillaria, according to a statement made at a meet- 
ing of the Manchester Philosophical Society, on Feb. 7th, by Mr. Binney, 
has not been properly understood. The Sigillaria, from clear evidence which 
he had obtained, was not only the chief pla,nt from which our coral deposits 
have been formed, but was really a tree which branched like the Lepido- 
dendron, and was not the strange stunted-topped plant which some vrriters 
have represented it to be. 
Connection between the existing Flora of Australia and the Plants of the 
Eocene Formation. — In the J ournal of Botany for February we find a trans- 
lation of a lecture delivered some time back by Dr. Unger, Professor of 
Botany in the University of Vienna. In this we perceive some startlmg 
resemblances shown to exist between the plants of Australia and those of our 
European Eocene deposits. Indeed, the similarity is so strikmg, as demon- 
strated in the numerous illustrative figures, that it is quite impossible to 
disagree with the conclusions drawn by the Professor ; viz., that during the 
Eocene period the two continents v/ere connected. Not only do we find, says 
the lecturer, several fragments of the polymorphous order Myrtacece, but it is 
plain that the genus Eucalyptus itself is represented amongst the fossils. Of 
several species the peculiar leaves, as well as the fruit, have been found. The 
same is the case with the Epacrids, although as yet only a single leaf fur- 
nishes evidence of the former existence of this now widely-distributed order- 
But, much more stress has been laid on the ProteacecB, than the Myrtaceae 
and Epacrids, as the characteristic plants of the Eocene period. We have 
found of them different leaves, fruit, and seed, and are even in a position to 
make out certain genera such as Banksia, Dryandia, &c. Thus it would 
appear that the Proteaceoe, now constituting the principal part of the scrub 
vegetation of New Holland, played a similar role during a former geological 
