NOTES. 
THE FRUITING OF CATENELLA OPUNTIA. — Algologists, and more 
especially those who have devoted themselves to a study of the reproductive organs 
of the Rhodophyceae, are well acquainted with the fact that many types produce 
cystocarpia and antheridia only at rare intervals. This is especially true of Catenella 
Opuntia. 
The first record of the discovery of sexual fructifications in the genus Catenella 
occurs in a paper published in the Transactions of the Linnean Society by Good- 
enough and Woodward in 1797 (Observations on the British Fuci, with particular 
descriptions of each species, vol. iii, p. 219). They noticed that certain specimens 
of the plant had the articulations modified in a peculiar manner, but from their 
description it is difficult to tell whether these were cystocarpia or tetragonidangia. 
According to Greville (Algae Britannicae, p. 167), Lightfoot (FI. Scot., vol. ii, 
p. 961) believed that fructifications of Catenella Opuntia occurred at the articulations 
of the frond ; Sir J. E. Smith attributed a reproductive function to the smaller joints 
of the internal filaments, and Dawson Turner (Synop. Brit. Fuci, 1802, p. 388) 
noticed certain bodies on the frond which he held to be of the nature of fructi- 
fications. Greville himself doubted the accuracy of these observations. 
Harvey (Phycologia Britannica, pi. 88, vol. iii) gave an imperfect description 
of the cystocarps of Catenella Opuntia obtained from material found by Mrs. Griffiths 
at Torquay. They have also been imperfectly figured by Crouan (Florule Finish, 
tab. xvi, Fig. 108), while J. G. Agardh (Epicrisis System. Florid., p. 586) described 
these structures from a single small specimen, the only one in his possession. 
Material bearing cystocarps has also been collected by Buffham (Quekett Micr. Club 
Journal, Ser. 2, iii, p. 257), but he gives no description of them. Harvey-Gibson 
(Journ. Linn. Soc. Bot., vol. xxix) states that unpublished observations on the cysto- 
carps of Catenella Opuntia had been made by Schmitz from specimens obtained from 
the Berlin Herbarium in 1885, gathered on the coast of Normandy and also at 
Ostend in 1832. No further finds of cystocarp-bearing plants are recorded until 
Harvey-Gibson collected fruiting material at the end of October, 1890, and again in 
June, 1891, on Puffin Island, North Wales. He described the fructifications in the 
Journal of the Linnean Society (Bot.), vol. xxix, p. 68. His material was collected 
from the protected faces of rocks near high-water mark. 
At the beginning of August in the present year (1912) I collected plants of 
Catenella Opuntia bearing abundant cystocarpic fruit, in a similar situation on Hilbre 
Island, Cheshire. Although the plant occurs plentifully on the less exposed faces 
of the rocks near high-water mark, towards the southern end of the main part of the 
island, the only specimens I found in the fruiting condition grew in a small crevice 
in the rocks which from its shape and position afforded special protection to the 
plants. 
I will gladly communicate fruiting specimens to any algologist who may desire to 
add such to his collection. 
HILDA COBURN. 
Hartley Botanical Laboratory, 
University of Liverpool. 
[Annals of Botany, Vol. XXVII. No. CV. January, 1913. 
