ZOOLOGY AND BOTANY, MICROSCOPr, ETC. 1035 



arises exoijenously, as in the embryo of Isoetes. Where the tuber is 

 relatively large, sporangia are borne on the elongated axis of the 

 parent tuber, and in such cases the new tuber originates adventitiously 

 as a depression at the base of the sporangium stalk. 



From the striking resemblance between Phjlloglossum and the 

 young plants of Lijcopodium cernuum, recently described by Treub,* 

 Bower proposes to regard Phylloglossum as a permanently embryonic 

 form of a lycopodiaceous plant ; but this awaits verification from the 

 study of the as yet imobserved oophore generation. 



Muscineae. 



Exudation of Water from the Female Receptacle of Corsinia-f — 

 Dr. H. Leitgeb points out the great importance to the Archegoniatse 

 (Vascular Cryptogams and Muscineoe) of the mouth of the arche- 

 gonium being kept perfectly moist during the period of imiDregnation ; 

 otherwise air-bubbles enter the neck and prevent the passage of the 

 antherozoids down the canal. This is in most cases insured by 

 contrivances for conducting drops of rain or dew to the archegonium 

 and retaining them there ; as, for example, the dorsal furrows in 

 Iticcia, the lobes and appendages of the archegonial receptacle in the 

 MarchantieaB, &c. In Corsinia inarchantioides the same end is attained 

 in a totally different way. The female receptacles here stand in the 

 central line of the foliar organ, in depressions from which the necks 

 of the archegonia project free into the air, each pit containing 

 usually several receptacles in different stages of development. These 

 are kept moist by a drop of water exuded from the tissue of the 

 Corsinia itself into the depression, and found only in those near the 

 apex of the shoot where the archegonia are in a receptive condition. 

 The drop of water is found during the three or four days over which 

 the impregnation of the various receptacles extends, and then dis- 

 appears. The author was unable to detect the nature of the tissue 

 by which it is exuded. He observed also in these depressions a 

 funnel-shaped mass of protoplasm somewhat similar to that in the 

 macrospores of Marsilea. 



Peristome of Bryacese.l — M. Philibert considers that in the 

 Diplolepideaj the internal row of teeth is formed by the detachment 

 of a second thin membrane, of more complicated network, separated 

 from the ordinary thick double membrane by empty cell-cavities. 

 By such a separation would be formed a series of sixteen free processes 

 such as are found in Funaria. That this is the true origin of the 

 internal peristome is confirmed by the fact that in some species of 

 Bryum it remains attached for a certain portion of its extent to the 

 outer teeth. In Funaria this adherence is less common, but occurs 

 in the rare F. sequidena. 



This interpretation becomes clearer when compared with analogous 

 structures in the Bryacoa>, especially in Bryum (Ptychoslomum) 



* See this Journal, ante, p. 277. t Flora, Ixvlii. (188.")) pp. .327-;50. 



X Rev. Bryologiijuc, xii. (1885) pp. G7-77. See lliia Journal, imk; p. 100. 



