5(5 THE PLANT WORLD. 



thought in mind one does not need to look at the representatives of 

 many genera before coming to the conclusion that the upper half of 

 the frond is more generally devoted to spore production than the 

 lower half. This is most strikingly shown in the Climbing fern 

 {Lygodiiim palmatuvi) also in our vicinity, and the Dryopteris 

 Noveboracensis growing in vast numbers along with the Wood- 

 wardia in question, shows the same thing in its fertile leaves and still 

 more prominently the common Polypody of the shaded rockeries. 



Just here there is another suggestion that this glance at the loca- 

 tion of fruitful pinnae brings to mind. There is frequently, if not 

 usually, a portion of the upper end of the fern leaf that approaches 

 sterility. The uppermost and terminal pinnule of the very ferns that 

 have been named are not the ones to be selected for their abundance 

 of sori. Scolopcndrmin vulgare may have all its sori in the upper 

 half of the leaf, but none of them are close to the tip. There is a point 

 in the fertile belt of pinnae of the Christmas fern {Dryopteris acrosti- 

 choidcs ) from which the reproductive tendency diminishes upward 

 as well as downward, and this is true of the Aspidiums and their allies 

 generally. This leads us up to the most striking illustration of the 

 thought in mind, namely, Clayton's Osmunda {Osmimda Claytoniand) 

 where as a rule the lower half of the upper half of each frond has 

 its pinnae fertile, while those above and below are vegetative in the 

 full meaning of that term. 



Returning now to our original "sport" of the Woodwardia, it is 

 seen that the largest of the uppermost dozen pinnae is at the summit; 

 but not without sori, while, as before stated, the lowermost ones are 

 sterile. It would seem that this freak would suggest that even in the 

 normal fertile leaves of the Woodwardia, or any other fern for that 

 matter, the reproductive activities are at their greatest in the upper 

 middle of the spore-bearing belt of the leaf. 



Rutgers College, October, iSgS. 



OBSERVATIONS UPON THE NEWER BOTANY. 



By Byron D. Halsted."^ 



LET me draw the outline of the problem that is to be investigated. 

 Imagine, if you will, you are standing upon a slope of land 

 facing the north, that the sun may not blind your eyes. To 

 the right is a wood lot, with its oak, hickory, chestnut, birch, 

 and other trees, standing neighborly, with arms interlocked, not too 

 closely for comfort, and through the branches the broken shafts of 



*From The Botanical Gazette for October, i8g8 



