Eatoni usually has its peculiar convoluted ridges, but one often finds 

 a spore which is cristate. Dodgei shows the same tendency to 

 vary, and to a greater extent Tuckermani,foveolata, and the echino- 

 sporas. In the latter one may at times find a spore, or perhaps sev- 

 eral in a sporangium, with crests running across the upper faces, 

 while even the spines below are variable. Other spores grown 

 with them, will have very long, slender, forked spines. Indeed, I 

 do not at present feel competent to fix the limits of the varieties, 

 but leave them where Engelmann did ; or, where specimens have 

 been referred to one or another of the varieties, the arrangement is 

 tentative only. 



I would remark, however, that while most specimens from my 

 neighborhood answer well to the descriptions of muricata and 

 Boottii, northern and mountain specimens usually have scattered, 

 short, blunt, flat spinules, most nearly corresponding to Braunii, 

 which, as originally described, is a mountain form. 



The leaves of all species bear a central bast-bundle, but none of 

 ours have more than four peripheral ones, and only four have them 

 at all, Engelmanni, Eatoni, Dodgei and Gravesii. In well devel- 

 oped plants of the first, all four are pretty constant, but young or 

 starved plants are liable to have only one or two, perhaps none. 

 Eatoni is oftener without than with them. 



All our species habitually have bi-lobed trunks, but tri-lobed 

 ones are not infrequently found, and in one species, Tuckerwani, 

 I find about 25 per cent, tri-lobed, and have found one four- and 

 another seven-lobed. While these plants appear to have been 

 chiefly tri-lobed from the seedling, occasionally one is found which 

 is apparently in process of transformation, One notable case was 

 a plant oifoveolata, collected at Newmarket, N. H., in 1899, which 

 bore a distinct lesion on one side, in which roots were forming. 

 The cortex between the lobe and lesion had not yet given way, but 

 in the natural course of events would soon have decayed, and prob- 

 ably the root-bearing area would have persisted, the plant thus be- 

 coming tri-lobed. Indeed, in the four- and seven-lobed Tucker- 

 inani specimens, there was evidence that a similar accident had be- 

 fallen them, and we might conjecture from this that the lower part 

 of the trunk is capable of becoming root-bearing, provided the cor- 

 tex be ruptured. Nothing conclusive has yet been observed on this 

 point and it needs a series of experiments to demonstrate the truth 

 or falsity of the hypothesis. 



