APHANIZOMKJSON. 279 



cimens of what I had presumed to be this plant in all its 

 stages (i. e. from its first to its last appearance as a colouring 

 matter), I was much pleased to have the conjecture verified 

 by microscopical examination. A portion taken from the 

 surface when it appeared pale green was, under the mi- 

 croscope, of as dark a hue as in July, whilst the blue and fer- 

 ruginous colours exhibited different stages of decomposition. 

 When in the most perfect state in which the plant has 

 occurred to me, the globules appear entirely filled with 

 granules ; but when very highly magnified are each found to 

 be surrounded by a hyaline membrane. The blue and ferru- 

 ginous tufts exhibited generally its empty globules and the 

 escaped granules scattered all about; but the former were 

 seen in every state from full to empty ; some had granules 

 only in the centre, others were half full, and some separate 

 globules were entirely filled with the granular mass. 



" When two of the spiral portions come in contact, they 

 have an elastic power, by which they can, though slowly, 

 disentangle themselves and separate from each other, a fact 

 which I witnessed in various instances ; but under such cir- 

 cumstance only did I ever perceive any motion in this Alga." 



" In some respects the Anab. spiralis resembles the Anab. 

 impalpabilis Bory, as described in the " Encyclopedic Metho- 

 dique ; " but its dull green unlustrous hue on paper is quite 

 opposed to that of the species just named, which is described 

 Preparee sur le papier, ou on a facilite son developpement, 

 elle est de la teinte la plus brillante, tirant sur celle de 1'oxide 

 du cuivre, et luisant comme si on 1'eut enduite d'eau de 

 gomme." Besides, were this species of the exact spiral form 

 of that under consideration, this character would not I con- 

 ceive have been unnoticed in the description." Thompson. 



33. APHANIZOMENON Morren. 



Char. " Filaments simple) cylindrical, flexile, membranaceous, 

 glossy, articulated, cohering together in fiat lamella 1 ,, lance- 

 olated at the apex, straight, or here and there inflated, full 

 of green matter, oscillating spontaneously, falling into 

 pieces." Morren. 



T 4 



