THE ANNALS 
AND 
MAGAZINE OF NATURAL HISTORY. 
[SECOND SERIES.] 
66 sesserseerseeeeeee DEY litora spargite muscum, 
Naiades, et circdm vitreos considite fontes : 
Pollice virgineo teneros hic carpite flores : 
Floribus et pictum, dive, replete canistrum. 
At vos, o Nymphe Craterides, ite sub undas ; 
Ite, recurvato variata corallia trunco 
Vellite muscosis e rupibus, et mihi conchas 
Ferte, Dez pelagi, et pingui conchylia succo.” 
N. Parthenii Giannettasii Ecl. 1. 
No. 25. JANUARY 1850. 
I.—Observations on the Conjugation of Closterium Ehrenbergii. 
By the Rev. W. Smiru, F.L.S. 
{ With a Plate. ] 
THE conjugation of Closterium Ehrenbergii (Menegh.), under 
the name of Closterium lunula, has been described in a paper by 
M. Morren, ‘ Annales des Sciences } Vaturelles,’ 2nd ser. tom. v. 
1836, but the phenomenon does not appear to have met the eye 
of any late observer im this country, and is wholly unnoticed by 
the acute and careful authors of the ‘ British Desmidiez.’ 
I have had an opportunity, during two successive seasons, of 
noticing the circumstance in question, and the facts elicited seem 
to vary in some important respects so materially from those re- 
corded by M. Morren, and are in themselves so different from the 
ordinary phenomena which acconipany the conjugation of other 
Closteria, or indeed of any other of the Desmidiee, that I have 
thought it might be interesting to those engaged in such inves- 
tigations to state the particulars which have fallen under my 
notice. 
On the 23rd March 1848, I first discovered Closterium Ehren- 
bergit in astate of reproduction. On this occasion the period of 
conjugation had evidently nearly expired, as but few individuals 
were in that condition, and the mucus stratum, which results 
from the aggregation of conjugating fronds, had almost wholly 
Ann. & Mag. N, Hist. Ser. 2. Vol. v. 1 
