four ntw Species of Fucus. 129
much has been already written upon that fubjed, the Society will perhaps excufe me if I trel'pafs Ibmewhat upon their time hy a flit^ht digreffion refpefting it. The fruit of Fucus Hypogkjfum, as is well known, is fometimes found in fmall globular caplulcs fituatcd upon the midrib of the leaves, while in other fpecimens no traces of thefe capfulcs are apparent, but minute dark, feeds are difcovered in two fmall rows on each fide of the midrib, and parallel to it : a circumflance which with fome botanifts has given rife to the conjecture that this Fucus may poflTibly be dioicous, while others have carried the matter fo far as to wifh to conftitute two diftin6l fpecies. The latter idea however is done away by plants being occafionally found in which both kinds of fruftification, as they are called, may be difcovered upon the fame plant ; and the former fuppofition has always appeared to mc equally ill-founded, from my once having examined a plant in which the capfule was aiSlually burfling, and the feeds partly difcharged. I have no hefitation in owning, that I never could account for thefe feeds, fuppofing them to be cafually scattered, adhering in fuch regular lines as is always the cafe ; nor can I fee any rcafon for that part of the membrane upon which they are difpofed being of a darker colour, and apparently thicker subftance, than the reft of the leaf : thefe are difficulties which I hope other botanifts will remove, but which do not appear to me of sufficient importance to induce me to accede to the idea of Fuci being raonoicous or dioicous. I am indeed on the contrary persuaded that they prove nothing, as many other Fuci, among which are to be enumerated the following, have their feeds equally contained in capfules, and afterwards difperfed upon the frond, though without the fame appearance of regularity: thefe are Fucus alatus^ ovalis, dafyphyllus, nrticulatus, kaliformis, clavellofus, teiiu'tjjimus, and pinmtljiaus. From a confideration of thefe and other circumstances, I have been led to conjefture, that in the above-mentioned Fuci
