THE MARINE ALGvE OF NEW ENGLAND. 2l 



and destitute of any general envelope. In by far the greater number of 

 genera tke spores are not formed by direet outgrowths from the tricho- 

 phore. In Callithamnion, for instance, the fertilizing influence is propa- 

 gated from the trichogyne, through the trichophore and the cells below it 

 which constitute the trichophoric apparatus, to certain lateral cells, from 

 which by repeated cell-division the spores are formed. In Dudresnaya the 

 cells of the trichophoric apparatus send out a number of lateral tubes, 

 which, in turn, convey the fertilizing impulse to certain modified branches 

 in other parts of the frond, so that, in reality, the cystocarp is formed 

 at some distance from the trichogyne by means of which it has been 

 indirectly fertilized. A similar mode of fertilization is known in Polyides 

 and, according to Professor Schmitz, in the Squamariece. The cystocarps 

 are sometimes naked, that is, without a special membranous envelope, 

 as in Nemalion, but they not unfrequently are contained in a concepta- 

 cle or pericarp. In the latter case, the development can only be studied 

 with difficulty, because the conceptacle, which originates from some of 

 the cells below the trichophore, develops more rapidly than the rest of 

 the cystocarp, and so shuts out from view the process of the formation 

 of the spores. It is impossible in the present article to enter into the 

 details of the development of the cystocarp in this complicated order, 

 but the reader interested in the subject is referred to the superb work 

 of Thuret and Bornet, Etudes Phycologiques, and the hardly less admi- 

 rable Notes Algologiqiies, of the same authors, for a masterly exposition 

 of the subject. 



MODE OF COLLECTING AND PBEPAELNG SEA-WEEDS. 



The collector of sea- weeds should be provided with a pail of tin or 

 wood, or, better still, with one of papier mach6 if it can be procured, in 

 which he should place a number of large wide-mouthed bottles and several 

 small bottles, and one or two vials filled with alcohol should not be forgot- 

 ten. A knife is needed for scraping crustaceous algae from stones, and a 

 geologist's hammer and chisel are often useful. A hand-net, with a long, 

 stout, jointless pole and net with small meshes is a necessity. Clothes for 

 wading are also indispensable, since the best collecting grounds are 

 below low- water mark. If the collector is not already sufficiently en- 

 cumbered, he may throw a common botanical collecting-box over his 

 shoulder, as it will serve to carry the coarser species. Collecting on 

 sandy or gravelly beaches is very simple. One finds there only the 

 Floridece and larger brown sea-weeds which are washed ashore after a 

 storm. It is only necessary to pull over the heaps of refuse at high- 

 water mark, or to dip up with a net the specimens which are floating at 

 low- water. Collecting on beaches is uncertain, because it is only at 

 certain times that specimens are washed ashore.. On rocky shores, on 

 wharves, and on the eel-grass we are always sure to find something. 

 One should examine the surface of rocks wet with the spray, the bases 

 of the stalks of the marsh-grasses, and even the surface of mud which is 



