ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 465 



continental authorities. 9. The reason why the leaf -scars are not found 

 is that when whole branches were shed it was unnecessary to shed the 

 individual leaves. 10. The increase in diameter of Lepidodendroid 

 stems, owing to secondary growth, is very slight. 11. The growing 

 points of Lepidodendron must have been of very great size. 



Anatomy of Epiphytic Lycopodiums.*— J. Ben Hill describes and 

 figures the anatomy of six epiphytic species of Lgcopodium, namely, 

 L. Bittardieri and L. varium from New Zealand, L. verticillatam and 

 L. Holstii from South Africa, L. Phlegmaria and L. carinatum from 

 Samoa. He gives the following summary of his results. 1. These 

 species showed great variability in the development and structure of the 

 stele. 2. The radial stele may be considered as the prevailing type, and 

 as the basis in most cases for modification to the other types found. 

 3. There are radial, parallel-banded, crescentic, and amphivasal steles 

 found in the same strobilus axis in L. carinatum, and all types but the 

 amphivasal in L. Phlegmaria and L. varium. 4. L. Billardieri is the 

 most constant in its stelar structure, with a type of stele so characteristic 

 as to make the species almost recognizable by the transverse section of 

 the stem. 5. L. verticillatum has generally a parallel-banded arrange- 

 ment of stele, although the radial stele lias been considered the prevail- 

 ing type in epiphytic species. 6. All attempts to place the species of 

 Lycopodium in definite catagories based on the character of the stele are 

 extremely uncertain, since there are exceptions in some species, and even 

 exceptions in different parts of the same stem in some species. 7. If the 

 character of the stele is in any way dependent upon varying conditions, 

 its use in phylogeny must recognize this fact. 8. The investigation 

 made confirms the idea that the radial arrangement of the stele, retained 

 persistently by the root, is probably the most primitive stem arrange- 

 ment, from which most known stems have departed. 



Stigmaria. f — 0. Lignier discusses the interpretation of the stock 

 of Stigmaria. In his resume he states that: — 1. The skeleton of the 

 stocks of Stigmaria resulted from the dichotomy of a rhizome, one of 

 the branches of which grew upwards and became the stem, while the 

 other turned downwards and ramified dichotomously. 2. The basipetal 

 extension of the secondary tissues due to growth in thickness of the 

 trunk enveloped successively the first branches of this ramification of 

 the roots and included them in the stock, which bore thus successively 

 in proportion as it increased in thickness, one Stigmaria at first, then 

 two laterally, then four diagonally, etc. 3. It is probable that an 

 analogous structure developed also from the plantule derived from the 

 macrospore. 4. Perhaps the obliquity and exogenous origin of the first 

 roots of modern Lycopodiacese on their stem are a reminder of this 

 ancestral arrangement. 



* Bot. Gaz., lviii. (1914) pp. 61-85 (28 figs.). 



t Bull. Soc. Bot. France, lx. (1913) pp. 1-8 (5 figs.). 



Oct. 21st, 1914 2 I 



