362 Mr. Hassall on the Branched Freshwater Confervce. 



at their bases ; reproductive bodies situated either in in- 

 flated cells, when they are formed by the union of the con- 

 tents of true contiguous cells, or in the bulbous portion of 

 the setae, which becomes much enlarged for their accommo- 

 dation. 



The reproduction of this remarkable genus has until very 

 recently been wholly unknown. M. Decaisne, in his memoir 

 on the Classification of the Algae, contained in the numbers of 

 the • Ann. des Sciences Nat./ for May and June 1842, alludes 

 to the mode of formation of the reproductive bodies by the 

 union of the matter of true cells in the same filament, but does 

 not appear to have noticed the second way in which they are 

 formed, viz. within the bulbous portion of the tube. The ob- 

 servations of M. Decaisne and my own remarks appear to 

 have been made nearly at the same period. 



In the above account of the reproduction of the genus Bul- 

 bochmte I have avoided using the term spore to designate the 

 condensed endochrome in the inflated cells which presents so 

 much the appearance of a true spore, for I conceive that it is 

 most probable that this separates, as in the other branched 

 species of Confervae, into numerous small reproductive gra- 

 nules. 



The genus Bulbochcete may be regarded as forming the con- 

 necting link between the simple and branched freshwater Con- 

 fervae ; it agreeing with the Conjugates in the equality of its 

 filaments, with the Vesiculasperms in the union of the con- 

 tents of two distinct cells, and probably with the branched 

 species in the separation of the condensed endochrome in 

 the inflated cells into numerous reproductive vesicles. 



But one species of this genus is described by British authors. 

 There are however, I suspect, not less than three or four di- 

 stinct species, which I would characterize as follows, refrain- 

 ing for the present from naming them, in the hope of having 

 further opportunities of examining them. 



1st sp. Bulbochcete setigera. Cells usually five times as long 



as broad. 



This I regard as the most common species of the genus, 

 and I have met with it in very great abundance in ponds on 

 Hertford Heath, High Beach, Cheshunt Common, as well as 

 other places. 



2nd sp. Cells usually three or three and a half times as long 

 as broad ; reproductive bodies formed by the union of the 

 contents of two adjacent cells, in one of which they are 

 contained. 



