10 BRITISH MARINE ALG. 
to be included in the Chlorosperms or green seaweeds; and this is another 
instance of the necessity, as already pointed out by me, of some little 
book-learning at first, otherwise many a pretty plant will be passed by 
unheeded or overlooked. The species in question consists of a bundle of 
purple silky filaments, several inches long, unbranched and very narrow 
throughout their whole length. The broadest filaments of this delicate . 
plant, under the microscope, are seen to be tubular, and to contain four or 
five rows of granular cells, a form of structure which connects these plants 
with the Ulvacew, otherwise to the ordinary observer, they would appear to 
belong to the Conferve, a genus of green unbranched plants which I will 
describe presently. 
The Enteromorphe, of which two common species make their appearance 
about high-water mark clothing rocks and stones with a slippery vesture 
of shining green, have been the cause of many a tumble to the unwary 
pedestrian on the sea shore. I have heard these pretty green plants some- 
times called ‘‘ sea-grass’”’ and ‘‘ mermaids’ hair,’’ and, indeed, some of the 
rarer and finer species may well be termed mermaids’ hair or sea hair. 
But first I must describe the two species that are met with everywhere, 
and these are Enteromorpha intestinalis and E. compressa. The former 
grows in tufts, and is simple, or unbranched; each frond is tubular, and 
somewhat constricted here and there, and in form resembles the intestine 
of an animal, hence its specific name; but EH. compressa (Fig. 8) is a 
branched species, and is compressed or flattened at the margin. These 
plants are very variable in length and width, the filaments of some 
specimens being very narrow, while others are as broad as Ulva linza, and 
very dark in colour. The largest specimens of Enteromorpha always 
appear to me to owe their unusual size to the action of fresh water; I 
have often seen specimens of E. intestinalis, as well as Ulva latissima, 
growing in streams which were scarcely even brackish, more than 2ft. in 
length, and of such breadth that they appeared like large green bags 
floating in the water. The structure of the Enteromorphe is very similar 
to that of Ulva; the whole frond is beautifully reticulated, the cells being 
arranged in fours, or multiples of that number, the endochrome or colouring 
matter of which at maturity is converted into spores. The fronds of these 
green plants are often found partially white, and sometimes wholly so. 
This is due not only toincipient decay, but because the spores have broken 
away from the cells, leaving the membrane of the plant colourless and 
unsightly. Then is the time to look for certain rare microscopic parasites, 
some of which have their special habitat on decaying fronds of Entero- 
morpha, as well as on those of the Ulwe. In addition to these two well- 
marked and easily recognised species, there are several others, more or 
less rare. Among these, the most interesting probably is the species called 
E. clathrata (Fig. 9). It grows abundantly in the rock pools all about 
Torbay, but being a summer annual, it loses much of its bright green colour 
towards the end of September, and soon after turns to a brownish yellow- 
In all stages of its growth the fronds are extremely slender, very much 
