A. Henfrey on the Higher Cryptogamous Plants. 27 
of peculiar organs, composed of four papilliform cells, enclosing 
a large globular cell in the centre. In one of these large spherical 
cells the young plant is produced. The nature of the structure 
was ouly briefly described in this paper for the purpose of show- 
ing its analogy with what occurs in Salvinia. 
In 1850, Dr. Mettenius* published an essay on the Propagation. 
of the Vascular Cryptogams, and in this is to be found a full de- 
scription of the organs mentioned by Hofineister and altogether 
overlooked by Dr. ©. Miller. According to this author, the large 
spores of Seluginella involvens possess two coats, each composed 
of two layers; and in an early stage of the germination, the inner 
layer of the outer coat, together with the inner coat, form the 
walls of a globular body which does not wholly fill the cavity 
enclosed by the outermost membrane. This globular body is 
firmly attached to the outer membrane immediately under the 
point of junction of the three ridges separating the flattened sur- 
faces.of the inner side of the spore. The globule enlarges until 
us walls come to be applied closely to the outer layer, completely 
filling up the large cavity. Then between the two layers of the 
inner coat, ata point immediately beneath the point of junction 
of the three external ridges, a process of cell-formation commen- 
ces, producing a flattened plate of tissue interposed between the 
two layers; this structure is the pro-embryo. ‘The cells are at 
* Beitrige zur Botanik. Heidelberg, 1850. 
