yill. ON THE MOIIPHOLOGY OF HEPATIC 



ELATERS, WITH SPECIAL REFERENCE 



TO BRANCHING ELATERS OF 



CONOCEPHALUS CONICUS. 



Josephine E. Tilden. 



The peculiar spring-like, strongly hygroscopic elater cells 

 which are mixed with the spores in the capsules of most spec- 

 ies of Hepaticae have long been known. To their comparative 

 morphology little attention, however, has been given. Com- 

 monly in the systematic works on the liverworts, after a brief 

 description of the most obvious characteristics, the further 

 consideration of the elater is neglected. It would appear, 

 nevertheless, that the elaters might properly receive extended 

 study, both on account of their remarkable mechanical function 

 and on account of their considerable range of variation in the 

 different genera. This paper is preliminary to a more extended 

 developmental study of elaters. 



Historical. It seems that the older writers conceived the 

 use of the elater to be that of a pedicel for the spores. One of 

 the earliest references at hand is that of Dillenius^ in which he 

 shows a figure of the elaters of Targionia and refers to the 

 Novus Genus of Michelius- where elaters are descrbed as slender 

 filaments covered with dust. Linnaeus describes Marchantia, 

 using the phrase "farina crinulo affixa."^ Ventenat,-^ in his 

 statement that the "seeds of MarcTiantia are inserted upon 

 elastic filaments," quotes directly from Marchant,^ for whom the 

 genus was named. St. Hilaire also refers to Marchant as his 

 authority for the same observation. ^ Withering^ makes the 

 general statement, with regard to the various genera of the 

 Hepaticae, that they have elastic cords, formed of one or two 



1. Dillenius, Hist. Muse. 532. Tab. LXXVlll, 9 B. 1741. 



2. MicheUus, Nov. Gen. 3. Tab. 3, fig. b. 1729. 



3. Linnaeus, Gen. PI. Ed. II. 506. 1742. 



4. Ventenat, Tab. du Rejrne Veg. 2: 42. "An. VII." 1799. 

 5 Marchant, Mem. de I'Acad. des So. 230. PL 5. 1713. 



6. St. Hilaire, Expos, des Fam. Nat. 1 : 26. "An. XIII." 1805. 



7. Withering. Syst. Ar. of Brit. PI. 1 : 363. PI. XIV, fig. 41, 51. PL XV, fig. 64. 1801. 



