THE HIGHER CRYPTOGAMIA. 83 



of water more than the membrane of the spore-mother- 

 cells themselves (PI. VI, fig. 23). The mother-cells of the 

 spores of all the true Jimgermanniae which I have examined, 

 those of Radula and Frullania, are rich in chlorophyll-gra- 

 nules. In Blasia pusilla the presence of chlorophyll is 

 limited to the tertiary nuclei destined for spore-forma- 

 tion, the substance of which seems usually to be coloured 

 green throughout (PI. V, fig. 24). 



The first investigations into the germination of the spores 

 of Jimgermanniae, are those of Hedwig.* They extend no 

 further than the protrusion of the first rootlet. The observa- 

 tions published by Nees von Esenbeck,f do not advance 

 the knowledge of this subject to any further point. Bis- 

 choff, eighteen years later, \ directed attention to the 

 germination of Pellia, up to the formation of the first shoot. $ 

 Bischoff's observations agree entirely with those of later 

 observers, even in the unimportant circumstance that he 

 represents the base of the germ-plant (the hinder part of 

 the multicellular spore) as a globular enlargement of too 

 great thickness. I have already spoken of the incorrectness 

 of the expression (Vorkeim) applied by Gottsche to the 

 first shoot of the germ-plant. Gottsche noticed, || although 

 not very clearly, the multicellular nature of the spores of 

 Pellia, and followed their germination, cell by cell, until the 

 perfect development of the first shoot, stating more intel- 

 ligibly the relation of the exosporium to the germ-plant. 

 Gottsche at the same time published an account of the 

 remarkable germination of Blasia pusilla ; he showed that 

 when the spore (after being sown) has become indistinctly 

 multicellular, a long, cylindrical, tubular cell shoots forth, the 

 end of which is developed into a cellular body, from which 

 at a later period the stem of the germ-plant is produced. 

 Lastly, Gottsche gave the first account of the germination 



* ' Theoria generationis,' Leipz., 1798, 17. 



+ ' Nova Acta,' A. C. L. N. C, xiii, 1 (1824), 165. 



% 'Handb. bot. Terminologie,' Bil. ii, Nurnb., 1842, 733, t. lvii, 2795-96. 

 These observations appear to have been made as early as 1828. See 'Bot. 

 Zeit.,' 1853, 14. 



Bischoff completed this work at a subsequent period by the publication of 

 further figures. See ' Bot. Zeit.,' 1853, t. ii, f. 1421. 



I| ' Nova Acta,' A. C. L., vol. xx, pars 1, 3S2. 



