158 SUMMARY OF CURRENT RESEARCHES KKLATING TO 



Reproductive. 



Ovules and Seeds of Cercis.* — J. A. Harris contributes farther 

 observations on the relationship between the number of ovules formed 

 and the number of seeds developing in Cercis. The author finds that 

 the type, variability, and correlation of the number of ovules and seeds 

 per pod differ in individuals and in different habitats, but there is 

 no reason for concluding that trees from different habitats can be 

 distinguished by their seeds. The correlation for the number of ovules 

 formed and the number of seeds developed in each pod of an individual 

 tree is always positive and of moderate to high intensity. " The rate of 

 increase in number of seeds developing per pod remains the same as we 

 pass from pods with the lowest to pods with the highest number of 

 ovules." The correlation between the number of ovules in each pod 

 and the number of mature seeds is negative and usually of very low- 

 magnitude. These results are based only upon mature pods of Cercis 

 canadensis and must not be regarded as of general application except on 

 the basis of further investigation. 



CRYPTOGAMS. 



Pteridophyta. 



(By A. Gepp, M.A., F.L.S.) 



Ophioglossum pendulum.!— L. C. Petry discusses the anatomy of 

 Ophioglossum pendulum, which shows great variability in certain 

 structures, such as the number of protoxylem strands (2 to 6) in the root, 

 and in the leaf-trace (3 to 12), these differences being associated with 

 the size of the organ concerned. Buds develop on the roots ; and 

 the connexion of their vascular structures varies greatly. In this 

 rhizome is an ectophloic siphonostele perforated by gaps of three kinds — 

 root, leaf, and incidental. Medullary strands consisting only of xylem 

 occur in some specimens ; and their occurrence is taken to support 

 the stelar nature of the pith. The strands which make up the leaf -trace 

 arise as a curved series which later form a circle ; but those strands 

 which belong to the edges of the curve later break off to supply the 

 fertile spike ; that is, the supply of the spike is marginal. 



Position of Buds in Botrychium.J — H. Woynar discusses the 

 position of the buds in Botrychium, which he considers characteristic 

 for each species, and which may therefore be used as a means of 

 diagnosis. The buds are certainly not absolutely stable in their 

 position, but pass slowly from one to another. The different arrange- 



* Bull. Torrey Bot. Club, xli. (1914) pp. 533-49 (4 figs.). 

 t Bot. Gaz., lvii. (1914) pp. 169-92. 



J Oesterr. Bot. Zeitschr., lxiv. (1914) pp. 101-7 (2 figs.). See also Bot. Ceu- 

 tralbl., cxxvi. (1914) p. 307. 



