INTRODUCTION TO CRYPTOGAMIC IJOTANY. 217 



which are often concentrically zoned, and resemble variegated 

 feathers, a resemblance which is so much the greater in con- 

 sequence of the beautiful fringe of hairs with which each band 

 is ornamented. Parallel, or rather concentric with the spores, 

 is a row of articulated threads, which have a strong resem- 

 blance to the elongated processes which contain the spermato- 

 zoids in Cutleria. They are indeed so like them, that in a 

 plant so closely allied it is impossible not to suspect similarity 

 of function. The endochrome is figured by Harvey as dividing 

 into four distinct spores. Taonia departs somewhat from the 

 wedgeshaped outline, differing at the same time in the details 

 of fructification. Cutleria has a flat multifid frond of a tawny 

 hue, with large fruit. The highest degree of development is 

 reached in Haliseris, which has a flat linear membranous 

 forked frond, threaded by a cartilaginous midrib. It is in 

 species principally of Zonaria, Padina, and Haliseris, that 

 the tropical and sub-tropical seas attain their maximum of 

 species. I am not aware that any are of practical utility. 



4. Laminariace^, Grev. 



Inarticulate, mostly flat, often strapshaped. Spores super- 

 ficial in indefinite patches, or covering the whole frond. 



200. The plants of this order attain frequently a very large size, 

 and are known by the mostly coriaceous fronds, and fibroso- 

 cellular consistence, and fruit which is dispersed in irregu- 

 lar superficial indefinite patches or covers the whole frond. 

 The frond itself is tubular, divided into chambers by transverse 

 partitions, or flat and solid, often entire, but sometimes pinna- 

 tifid, sometimes divided into straplike lobes, and in some cases 

 increased by repeated fissures upon a given normal system. 

 In general there are no bladderlike inflations, but occasionally 

 there is one or more at the base of every frond. In some 

 the frond is regularly crlbrose, and in more than one the edges 

 are highly curled and plaited. The stem is sometimes absent, 

 but is mostly of large dimensions, generally simple, but some- 

 times repeatedly divided. 



201. In many perennial species, the stem increases in size 

 year by year, a new frond springing from its apex, and 

 replacing the old one, which at last separates from the point of 



