Hep ft ticw of North America. 



and raised on a pedicle in the f oliaceous species ; in the thallose 

 species it may be sessile on the surface of the thallus (Sphcero- 

 ctfrpus), immersed in it (Fimbriaria, Pellia), or in a sessile or 

 pedunculate disc-like receptacle, sometimes called an andro- 

 cephalmn (Marchantia^ Axf ere/la-). The antheridia coHectively 

 are sometimes referred to as the androecium. 



The antheridia contain a large number of small bodies sus- 

 pended in a mucus, which consist essentially of spirally curved 

 slender threads, provided at the end with cilia for purposes 

 of motion; these are the antherozoids (Lat. anthera, anther, 

 Gr. zoon, an animal, and eidos, form), and are analogous to 

 pollen. 



Archegonium. The female organ is a flask-shaped body 

 which, when mature, has an orifice at the apex opening into 

 the interior, where is found a globular cell known as the 

 oux/ there (Gr. oon, an egg, and sphairos, a sphere). 



The process of fertilization consists of a union or conjunc- 

 tion of the antherozoid produced from the male organ, and the 

 oosphere produced by the female, an end made possible by the 

 motile power of the former. The fertilized oosphere developes 

 into the " alternate generation," or sporogony phase. 



In most of the true Liverworts (MARCHANTIACEJE) the ar- 

 chegonia are situated on the under side of a usually peduncled 

 receptacle, which, as it bears the so-called fruit, is known as 

 the carpocephalum (Gr. karpos, fruit, kephale, head). 



Involucres. Immediately surrounding the archegonia, 

 and usually formed after fertilization takes .place, is a tubular 

 or somewhat prismatic organ, which may be called the inner 

 involucre;* surrounding this is the outer involucre,* which is 



* I have used the above terms at the suggestion of Dr. Gray, not- 

 withstanding the different use of writers in both Europe and America. 

 American writers have largely followed Nees von Bsenbeck, in Synopsis 

 Hepaticarum (1844), while recent European writers have revived the 

 nomenclature of Dumortier, used as early as the publication of Sylloge 

 Jungermannidearum (1831), and perhaps earlier. It would seem that a 

 rearrangement of terms, adjusted to both Musci and Hepaticx, might 

 profitably be made. That no error be made by those referring to other 

 writers, the following comparison is given : 



Inner involucre (as above) = colesula (Dumortier, Lindberg) = peri- 

 anth (Nees von Esenbeck, Sullivant, Austin) = perichretiurn (Ekart). 



Outer involucre (as above) or simply involucre = perichsetium (Du- 

 mortier, Lindberg) = involucre (Nees von Esenbeck, Sullivant, Austin) = 

 calyx (Ekart). 



