375 



Iheir peculiar function may be I cannot even conjecture : T do not 

 find anything analogous either on E. Mackaii or on E. variegatum.* 



Branching. — On what the branching depends I am unable to say. 

 It is sometimes not easy to distinguish between branches and stems ; 

 the only distinction I can suggest seems almost a truism. Stems arise 

 from the root, and branches from the stem. As the root is always black, 

 they can therefore be in general distinguished, if this method of distinc- 

 tion is attended to. And I think it will generally be found that E. va- 

 riegatum is the only plant of the three that can strictly be said to branch 

 from the base, inasmuch as it does so in all circumstances, while the 

 other two can scarcely be said to throw out basal branches, except 

 when the stem has been broken off, or has decayed almost at the root. 

 The three are occasionally branched near the top of the stem. With 

 respect especially to E. hyemale and Mackaii, it may be said that this 

 appears, in every instance, an effort of the plant to prolong its exis- 

 tence. It is always in older or broken stems that such branching takes 

 place. E. hyemale is least subject to this manner of growth, and 

 when branched, rarely throws out more than a single branch. I have 

 not observed one above two or three inches long, except in the solita- 

 ry instance of the stem before described. Sometimes, instead of a 

 branch, a single catkin, and more rarely a pair of opposite catkins, 

 appears. 



E. Mackaii is, for the most part, unbranched, but of the three it is 

 most liable to branching from the upper part of the stem. In this 

 case the most frequent number of branches is three, and these, spring- 



* Subsequent observation has enabled me to ascertain the following facts. The 

 sheaths which in E. hyemale surround the base of the pile of cones, are the rudiments 

 of several of the upper articulations of the stem. The base of the pile embraces the 

 rim of the innermost sheath, and within these the catkin and its sheath are, in their 

 geiTOinal state, completely enclosed. It is only when these incipient internodes prove 

 abortive, that they appear of a texture similar to that of the crowning deciduous pile. 

 Thei/ are entirely destitute of teeth. 



The apex of the stem of E. Mackaii, previously to the appearance of the catkin, 

 proves, when dissected, to be composed of the converging teeth of a sheath which en- 

 closes several others disposed in a similar way, and having long, black, subulate teeth, 

 like its own. As in E. hyemale, the germ of the catkin is found within, thus pro- 

 tected in its embryo state. The manner of growth in E. variegatum is exactly the 

 same, but the teeth in every stage are somewhat white at the edge. 



What length of time stems thus gradually developed require to attain their full 

 growth, I cannot say. This, aud many other particulars respecting these plants, might 

 form very interesting subjects of observation to those by whom they are cultivated, or 

 to those who have leisure to study them in their natural state. 



