■^6 EQUISETACEiE. 



differ as to what entitles a plant to specific rank, and how 

 unsatisfactory a condition classification is in this country at the 

 present time. I must likewise call attention to a discovery 

 recently made by a gentleman Avell known in the botanical world 

 for his work amongst Chara. I refer to Mr. W. H. Beeby. Mr. 

 Beeby seems to have found E. litorale in Surrey. He has pub- 

 lished a full account of the plant in the March, 1887, number of 

 i\\Q/ourfial of Botany. This plant is figured on the first page. 

 Mr. Beeby observes that " the most noteworthy features about 

 this plant are the abortive spores and the absence of elators." 

 Hence Dr. Milde calls it " one of the most remarkable of Crypto- 

 gams." By several authors it has been considered a hybrid 

 between E. arvcnse and E. Itinosum, but Dr. Milde concludes by 

 saying (" Die Hoheren Sporenpflanzen," p. 114) " that, consider- 

 ing the wide range of the plant, this supposition seems doubtful. 

 Hybrid cryptogams in other cases, always appear singly, and as 

 extraordinary rarities. The spores and sporangia are aborted in 

 all the stations. Nevertheless, solitary green normal spores may 

 always be found. At all events, I think, the life-history of this 

 plant is not yet complete. Duval-Jouve considers it a good 

 species, not a hybrid." 



The Bath Flora contains five species of Equisetum, viz. — E. 

 arvetise^ L., E. maximum, Lam. {E Jinviaftle, S)m.), E. palusire, L., 

 E. limosum, L., and E. hyeniale., L. " The largest Equisetum of the 

 present day," writes Berkeley, " is not to be compared with the 

 noble representatives, as Calamites, which occur in the Coal Mea- 

 sures and the New Red Sandstone. True Equiseta also occur in a 

 fossil state." But more on this subject hereafter. 



I will now attempt to describe the form, structure, and habit of 

 a well-known representative of the genus, and then call your 

 attention to the life-history of the plant. Horsetails are vascular 

 cryptogams. They possess true vessels and are characterised by 

 the development from the spore of a leafless prothallium. This 

 prothallium is above ground and green. The aerial stem springs 

 from a creeping rhizome, which produces at its nodes a number of 

 adventitious roots. The stem is herbaceous, usually furrowed, 

 simple or branched, jointed, and provided at the joints or nodes 

 with toothed sheaths, formed by the coalescence of the leaves at 



