140 THE PHENOMENON OF 



formation of gonidia seems to occur sometimes together 

 with the spore-formation, and this in a double way. The 

 formation of numerous small swarmers in unconjugated 

 cells is mentioned by Ralfs as a not uncommon phe- 

 nomenon, but in so indistinct a way, that we cannot form 

 a satisfactory idea of it.* 



The active corpuscles found by Ehrenberg in a 

 Closterium, which he described as monad-like Infusorial 

 animalcules, under the name of Bodo viridis,^ might be 

 referred here. 



According .to Morren, J there is a totally different 

 process in Closterium Lunula, where, through conjugation 

 of two individuals, a single large active germ-cell is 

 formed, which commences a revolving movement in the 

 connecting canal of the parent-cell, already inside the 

 coats, then leaves the torn coats, and, after swarming 

 from ten to twenty minutes, sinks down and immediately 

 germinates, /. e., becomes elongated and returns to the 

 form of the old Closterium. 



If these statements of Morren are correct, there occurs 

 in the Closteria a double character of the reproductive cells 

 formed through conjugation, these sometimes appearing 

 as direct germ -cells (gonidia), and sometimes as true seed- 

 cells, it being uncertain whether the two cases occur in 

 one and the same species, or separately in different 

 species. The two-fold fructification of Vauclieria has 

 been spoken of already above (p. 128) ; it follows also, 

 from the observations of J. Agardh, || that large spores 

 are formed in addition to the small gonidia in Bryopsis. 

 Moreover, the simultaneous occurrence of gonidia and 

 spores is beyond doubt, in the large genus (Edogonium 



* Ralfs, 'the British Desmidiea;, p. 9. 



f Ehrenberg, ' Infusionsthiercheu,' t. ii, f. 15. 



% Morren, ' Menioire sur les Closteries.' ('Ann. des Sc. nat.,' v, 1836.) 

 (See also Smith, 'Ann. Nat. Hist./ 2d ser., vol. v, 1. A. H.) 



It is remarkable that Ralfs, who has seen the formation of spores in so 

 many Desmidiacea;, says nothing about it in reference to this very Closterium 



Lttiitila, and the allied species Cl, Elircnberr/ii and moniliferum . 

 |! J. Agardh, 'Alga; maris mediterranei' (1 



(1842), p. 



