372 Anatomie. — Descendenz und Hybriden. 



and stem above ground being leptocentric, but simpiy collateral in the 

 axis of the inflorescence, in tiie peduncles and in the leaves. This struc- 

 ture is also linown from Roxburgliia in accordance with the investi- 

 gations of Mr. Lachner Sandoval. This peculiar structure, where 

 the leptome is completely surrounded by the hadrome, is well known 

 from the rhizomes of many Monocotyledones, basides from mestome- 

 bundles of certain Dicotyledones, which are located in the pith. But while 

 such lepto-centric Strands appear to be principally observable in storage- 

 organs and tissues: rhizomes and pith, Ihey are, furthermore, met with 

 in the stem above ground of Roxburghiaceae. Theo. Holm. 



Lock, R. H., St u dies in Plant Breeding in the Tropics. 

 (Annais Royal Botanic Gardens. Ceylon. Vol. II. p. 299— 

 356. 1904.) 



The majority of these experiments were concerned prima- 

 rily with the acclimatation of plants from a more temperate 

 country, and with the production from these, by crossing, of 

 strains better adapted to a tropical climate. Tne number of 

 plants found suitablc was small, several of those tried hardly 

 growing at all. The majority of European plants tested only 

 grew well during one season of the year and there were seri- 

 ous difficulties in the way of raising several generations in one 

 year. Varieties of the common pea and maize afforded the best 

 results and the general trend of the experiments was to con- 

 firm the results of observers in Europe and America as to 

 the excellence and accuracy of Mendel's work. 



A general resume is given of the work of investigators 

 previous to the discovery of Mendel's papers and of Men- 

 del's observations. 



The following summary by the author serves to indicate the 

 general results obtained from actual experiments, an accoimt of 

 the details of which it is impracticable to give in a brief note : 



1. Mendel's observations were confirmed for the cate- 

 gories smooth wrinkled and green: Yeilow using Telephone 

 and Telegraph crossed with a yeilow native pea. A doubtfui 

 exception occurred in the case of one cross. 



2. Also for the allelomorphs coloured and white flowers 

 on a large scale in two cases, and for presence and absence 

 of parchment layer in one case. 



3. In the colour of the testa certain complications occur. 

 These are described in terms of Mendel's theory by the aid 

 of the hypothesis of latency. 



4. The shape of the seeds of peas depend upon several 

 factors of which some account is given, 



5. The time of flowering of hybrid peas showed in one 

 instance a correlation with the colour of the flowers. 



6. Some of the observations of Correns upon maize were 

 confirmed. The process of recrossing with the recessive was 

 carried out on a considerablc scale in one case and M e n del's 

 conclusion fully confirmed. In the case of the allelomorphs blue 

 and non blue aleurone layer, Mendel's law was shown to hold 



