PHYSIOLOGICAL BOTANY. 



297 



the middle of it a cylindrical portion is found, which con- 

 sists of large transparent cells, which the author regards 

 as the embryo. The seed of Hydnora resembles that 

 of Eafflesia in many points. Its nucleus consists of a 

 dense albumen, in which a spherical embryo is found. 

 In Cytinus the seeds are minute, and retain at their base 

 the bipartite membrane, which may with most probability 

 be considered as a prolongation, of the testa. The latter 

 is easily separable from the nucleus, which appears to 

 consist of an uniform cellular mass, as in the Orchidacea3. 

 He finally asserts that vascular tissue is not absent in the 

 Rafflesia and Balanophorese, and adds, that frequently, 

 plants which are very different in external aspect, are of 

 the same internal structure ; I might add, as in Cycadese 

 and Coniferse. Lastly, he gives a botanical description 

 of the female flowers and fruit of Eafflesia Arnoldi and 

 Hydnora Africana. 



On Macrozamia Preissii. By G. HEINZEL. Nov. 

 Act. Acad. Leop., vol. xxi, pt. i, p. 203. This forms an 

 inaugural dissertation, which appeared at Breslau, and 

 well deserves to be received into this work. The de- 

 scription of the plant is very good, and great attention is 

 paid to the physiology. The stem and leaves are not 

 treated of, although these are of great importance, but 

 only the male and female organs of generation. It is a 

 very remarkable circumstance, that the hard unilocular 

 anthers are irregularly produced from the scale in most 

 species. The author describes very accurately a minute 

 pedicle upon which the anther is formed ; I have detected 

 it in other Cycadeae, and always find it to contain a vas- 

 cular bundle. The author then advances an adventurous 

 morphology, according to which the scales merely con- 

 sist of convoluted stamens (filaments). These strained 

 hypotheses should not be had recourse to in matters 

 relating to the vegetable kingdom, and no morphology at 

 all is far better than a forced one. With regard to the 

 ovule, he does not follow R. Brown, but thinks that what 



