THE HIGHER CRYPTOGAMTA. 441 



processes of embryo-formation, than to indicate in what they 

 agree. One of these differences is the cell-formation inside 

 the pollen-grain, but the principal one is the development 

 of the endosperm and of the corpuscula, a process exactly 

 analogous to the formation of the prothallia and archegonia 

 of the vascular cryptogams, and which is entirely wanting 

 in the phsenogams. The whole series of developmental 

 processes which occur in the Coniferae between the filling 

 of the embryo-sac with the cellular tissue of the endosperm 

 and the production of the germinal vesicles in the corpus- 

 cula, is entirely passed over in the phaenogams. Here the 

 germinal vesicles are formed immediately in the embryo- 

 sac. In the phaenogams there is no vital phenomenon 

 analogous to the development of the prothallia and of the 

 endosperm of gymnosperns, just as in the cryptogams and 

 the Coniferae there is no analogue to the endosperm- 

 formation which takes place in so many phaenogams after 

 the arrival of the impregnating organ at the embryo-sac. 

 The breaking up of the pro-embryo of the Coniferae into 

 a number of independent suspensors is a phenomenon of 

 the most peculiar kind, to which nothing amongst the vas- 

 cular plants bears any resemblance,* and to which the 

 division of the spore (i. e. the mother-cell of the oospores) 

 of Fucus into several cells capable of impregnation and 

 developmentf is hardly analogous, inasmuch as with the 

 latter process the impregnation of the free spore commences 

 and forthwith terminates. 



The observations contained in the following note are the 

 result of investigations made subsequently to those detailed 

 in Chapter III. These inquiries have led to the conclusion 

 that Frullania— and probably also Lophocolea bidentata and 



* The formation of the pro-embryo of Loranthus europcetis out of four longitu- 

 dinal rows of cells may be looked upon as a slight indication of this. One only 

 of these cells, the terminal cell, becomes transformed into an embryonic globule. 

 (Hofmeister, in ' Abb. Kon. Sachs. Ges. d. Wiss.,' vi, 543. 



t Thuret, 'Ann. d. Sc. Nat.,' iv Ser., 1854, p. 273.) 



