216 ENGLISH BOTANY. 



[0. connivens appears to be but a sexual state of C. fragilis, as 

 strictly it only differs from that plant in sex ; the greater incurving 

 of the branchlets and shortness or absence of bracts given as dis- 

 tinctive marks are variable and unreliable characters. In the typical 

 form of 0. connivens (the branch and magnified portion of stem, with 

 the more incurved branchlets represented on Plate 1921, which I have 

 drawn from a typical specimen of Salzmann's in the Kew Herbarium), 

 the branchlets are very much incurved and the bracts absent or rudi- 

 mentary ; but in the British specimens seen, the bracts are nearly 

 half as long as the nucule, and the Slapton plant (a branch and 

 magnified portion of a branchlet of which is shown on Plate 1921, 

 taken from a specimen in the collection of Mr. Arthur Bennett of 

 Croydon) has the branchlets only slightly incurved, whilst the Gosport 

 specimen in Mr. Borrer's Herbarium (now at Kew) has only a few 

 whorls of branchlets strongly incurved as in Salzmann's plant (not 

 all of them as shown in ( Journ. of Bot.' 1880, t. 207, f. 3), and the 

 rest but slightly incurved as in ordinary C. fragilis.] 



0. fragilis bears a close resemblance to some states of C. aspera, 

 but is without the very distinct spine-cells [characteristic of that 

 species. Some forms of C. fragilis, however, have minute wart-like 

 or papilliform spine-cells, and sometimes the spine-cells of 0. aspera 

 are reduced to a similar condition, it then becomes difficult to dis- 

 tinguish the two species, the only ^distinctive character (besides that 

 of sex, on which no reliance can be placed) appears to be that of the 

 bulbils ; in 0. aspera these appear to be always simple, consisting of 

 a single, smooth, rather large, globose cell, and although two or more 

 such bulbils may arise from the same node, they are not united to 

 each other in a mass ; whilst in C. fragilis the bulbils are always com- 

 pound, consisting of numerous very small cells united into a granu- 

 lated mass]. The globules in C. fragilis are brilliant scarlet, and 

 contrast well with the bright green of the plant ; they are very 

 evanescent, and after their fall the specimen might be mistaken for 

 the female of a dioecious species. 



[The Kew Herbarium contains a specimen of C. fragilis from the 

 hot springs of Iceland, on the label of which it is stated that, " the 

 temperature of the spring in which this plant was growing was such 

 as to boil an egg in four minutes." A remarkable fact if the water 

 was really so hot at the exact spot where the Chara grew, as one would 

 scarcely expect protoplasm to retain vitality at a temperature high 

 enough to coagulate albumen.] 



Fragile Chara. 



