148 MORPHOLOGY. 



them. In a few instances germination has been observed in more deve- 

 loped Algae, as, for instance, by Martius *, Agardh, and Kutzing, with- 

 out, however, their having had regard to the most essential points, viz. 

 the origin of new cells. The self-division so much insisted upon by 

 Meyen f has not been established by observation, excepting in the case 

 of Diatomece, and other doubtful organisms, but has merely been as- 

 sumed. In Hydrodictyon utriculatum a young plant is developed within 

 a cell in an unknown manner.^ Mohl thinks he has seen a multipli- 

 cation of cells by division in Conferva glomerata. We are, however, 

 indebted to Nageli for elucidating this relation, as well as the whole cel- 

 lular formation, of the Algce, by showing that all increase of cells in 

 the AlgcB depends upon the second type of cellular formation ( 14). 



81. In the simplest forms of Alga, the plant itself is the parent 

 cell (sporangium) of the spores (Protococcus). In the thread-like 

 Vauclierice, a portion of the cell expands spherically into a spo- 

 rangium. In those composed of many cells the sporangium is 

 formed from one individual cell which, at times swelling into a 

 spherical form, furnishes the sporangium (CEdogonium vesicatum). 

 In the case of the greater part, however, we know but little of 

 the formation of the spores. In the more complex Floridea there 

 are apparently two kinds of spores in the different individuals. 

 Some enclosed in large numbers in a sporocarp (Kiitzing's Kapsel- 

 fruchte) are developed in a manner with which we are still unac- 

 quainted : the others (Kiitzing's Vier ling sf rue lite) are formed, accord- 

 ing to Nageli, exactly like the pollen-granules of the higher plants, 

 in a parent cell (sporangium), which sometimes becomes subse- 

 quently absorbed and disappears. |] The different forms of fruits 

 are either scattered, heaped together, or again frequently united 

 upon peculiarly formed lobes of the plants (receptaculum). 



Here, again, we have every thing shrouded in the greatest darkness. 

 Not that the water contains marvels, as Link declares, but that it has 

 been examined with the most unsatisfactory observation, combined in 

 some degree with an unrestrained fancy. In such a state of things there 

 cannot of course exist any thorough well-grounded study of the law of 

 development. I have myself unfortunately been unable hitherto to make 

 any more comprehensive observations. 



In certain respects, Kiitzing's Phycologia generalis forms a new epocli 

 in the study of the Algce, and, notwithstanding the constant and reiter- 

 ated changes and enlargements which he superfluously makes in the 

 terminology, and the deficiency which is throughout observable of accu- 

 rate observations upon the law of development, his work furnishes us 

 with the first attempt at arrangement of the greater part of the mate- 



* Martius, Nov. Act. Leopold. Carol, ix. p. 217. 



f Meyen, Physiologie, vol. iii. p. 440, &c. 



J Vaucher, Hist, de Conf. 



" Vermehrung der Pflanzenzelle durch Theilung." Multiplication of the vegetable 

 cell by division. Tub. 1 836. 



|| This Nageli maintains at any rate (loc. c/.), whilst Deeaisne (Archives du Mus. 

 d'Hist. Nat. vol. ii. ; Plantes de PArabie heureuse, p. 112.) positively maintains the 



