3 



foveolata, and muricata to Newmarket, N. H. Underwood found 

 some peculiar plants, not clearly referable to any published species, 

 at Goshen, Conn. The spores are either abortive or unripe, and 

 unsatisfactory for study."" 



It is hoped collectors will call my attention to the many gaps in 

 this list, that I may fill them. 



A critical study, however, shows the remarkable fact that ri- 

 paria and lacustris, tho formerly considered common, are very rare 

 and have not been collected in recent years. It is true they have 

 been reported from various localities, but all such specimens which 

 have been accessible to me, have proven to be either Engelmanni, 

 Tuckermani, Tuckermani borealis, or an undescribed species. 

 It is unsafe to draw conclusions until some of the old material has 

 been re-examined, which I hope will be in the near future ; but 

 there is a growing probability that the former has rarely been met 

 north of the Delaware, and that the latter in its typical state is not 

 American. I cannot agree with Dodge in his determinations as 

 regards these species, and identify them mostly as Tuckermani. 

 Incidentally, his saccharata from the Merrimac is immature Braunii. 



There is one other point in his work to which I take exception, 

 and that is the theory of hybridity of our species. Tho this may 

 well occur, I have never seen a case which I thought called for that 

 explanation. Eatoni, as is well known, usually bears only female 

 sporangia, only one plant in two or three hundred bearing male 

 spores, and then the sporanges occupy no regular zone, but are 

 intermixed with the others. It is evident, then, that this would be 

 a very good plant to experiment upon, as the macrospores could be 

 easily obtained without microspores. This has been done by Mr. 

 T. C. Palmer, who, I hope, will soon publish the results. I will 

 anticipate this, however, by stating that while straight cultures 

 yielded plants, attempted crosses between Eatoni and Dodgei or 

 Engelmanni were negative. So we have presumptive proof that 

 hybridity is extremely rare, if not altogether absent. Mr. Dodge 

 based his presumption on spore characters only, a very unsatisfac- 

 tory character, inasmuch as the sculpture of spores of all species is 

 very variable, in the echinosporas often confluent into walls, espe- 

 cially in muricata; while in Tuckermani spores are often found 

 mixed among normal ones that have the crests, or some of them, 

 broken up into spinules. As these spores have been found in 



* Additional specimens from I/ynn, Conn., collected by Dr. Graves, prove 

 this to be an undescribed species. It is inserted under the name of /. Gravssii. 



