10 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



ties. Tlie latter is a common species of brackish bays and coves. If 

 we add ZannichelUa jxdustris, a species closely related to Ruppia^ and a 

 few species of Fotamogeton, which occasionally make their way into 

 brackish-water ditches and streams, we hare completed the list of floAver- 

 ing plants which the student of marine vegetation is likely to meet on our 

 coast. Excepting the few flowering plants just named, and a few Characecc, 

 an order whose place is doubtful but which is now generally placed near 

 the mosses, which probably inhabit our brackish waters, our marine 

 flora consists wholly of Thallophytes, the lowest division of the Crypto- 

 gams^ the species of which are supposed to be destitute of any true axis 

 and leaves such as are found in the higher plants. The Thallopliytes have 

 been divided into three classes, Algcv^ Fungi, and Lichens. This classifi- 

 cation, as we shall see, is based on physiological rather than on morpho- 

 logical grounds, and is very far from being satisfactory; but, although 

 new classiticatious have been proposed, which, in time, will almost cer- 

 tainly supersede the old, at present it is iuipossible to ignore the old 

 divisions, which may be said rather to be convenient than to be based 

 on accurate knowledge of structure and development. 



Of the three old groups, the Algcv may be described as Thallopliytes 

 which grow submerged in water or in wet places, which contain chloro- 

 phyl, or leaf-green, and which are able to transform inorganic into or- 

 ganic material, or, in other words, to support themselves from the inor- 

 ganic matter about them. The Fumji do not grow submerged, do not 

 contain chlorophyl, and are unable to change inorganic into organic 

 matter, and hence must live as parasites upon bodies which contain organ- 

 ized matter. The Lichens were sui3posed by the older writers to be distinct 

 from alga? and fungi, and characterized by having in their interior certain 

 green bodies known as gonidia. It is to the first of the three divisions 

 named, the alga?, that, with very few exceptions, all the strictly marine 

 plants belong. How unscientific the division into algre, fungi, and lichens 

 is may be seen by the fact that on our. coast there is one species of fungus 

 which grows submerged in salt water, an undescribed species of Sphceria^ 

 which is parasitic on the stems of the large devil's apron, Laminaria 

 longicriiris, A few species of lichens grow between tide-marks, and sev- 

 eral in iDlaces exposed to the spray. Yerrucaria mucosa T. Fr. is abun- 

 dant on our northern coast, and might be mistaken by a collector for 

 Isactis plana. Yerrucaria maura T. Fr., and one or two other Yerru- 

 caria' , are rather common near high-tide mark, but are not generally sub- 

 merged. Practically speaking, then, when we speak of our sea-weeds 

 we refer merely to the algfe, which constitute ninety-nine one-hundredths 

 of the flora. 



Harvey, in his Xereis, divided alg?e into three classes, Melanospermea\ 

 Rhoclospermea^j and Chlorospermew. These three classes are distinguished 

 by their color, the first being olive-brown, the second red or purple, 

 the third green. This classification, which answered tolerably well for 

 distinguishing the species at sight rests, upon what modern researches 



