4 University of California Publications in Botany [Vol. lo 



but be decidedly different at maturity in a particular character or 

 characters, the differences being due to causes physiological and not 

 yet explainable, and the deviation from the normal not be heritable. 

 Again two plants of the same lineage may by chance get started in 

 different habitats in the same locality and at maturity be quite unlike, 

 e.g.. in size, one typical of the species growing in a belt of optimum 

 conditions for that species, and the other a dwarf merely, due to being 

 removed from such a belt of optimum growth. 



In passing I may say that the belt of optimum growth is not the 

 same for all species of Fucus. Some species or forms thrive only in 

 the extreme lower littoral belt, others in the middle, and still others 

 in the narrow belt along the extreme high-tide limit. It cannot be 

 argued that the species along the extreme high-tide limit are neces- 

 sarily there by chance and represent dwarf specimens. Fucus 

 evanescens f. rohustus may be found in such a belt extending along 

 the coast for miles w'here no other species or specimens exist, and yet 

 the rock ledges in such localities are continuous from far above the 

 high-tide limit to below the low-tide limit. Specimens of any species 

 may, however, be stranded in the upper tide limits, e.g., on mud flats, 

 and may leave offspring which may develop into seemingly distinct 

 forms. I have seen this demonstrated to my entire satisfaction in tlie 

 case of the so-called nanus forms. These forms are merely transitory. 

 I have seen acres of territory bearing such plants of any species that 

 happened to be growing in the vicinity, the most of which never come 

 to the fruiting period and are always more or less, usually profoundly, 

 distorted and dwarfed. Thus it is quite essential to know the habitat 

 of a plant w^hen attempting to place it. 



In this paper I am describing three new forms of Fucus seemingly 

 quite distinct from each other genetically, and apparently distinct 

 from all other entities, but which possibly may be only environmental 

 forms. They all fruit abundantly and, to all appearances, from oliser- 

 vations made during only one season, they perpetuate themselves and 

 remain constant. These are forma cuncatus, forma depauperatus, 

 and forma oregoncnsis of Fucus evanescens, found growing in Coos 

 Bay, Oregon. They are profoundly different in shape, size, and color 

 from any forms growing outside of the moutli of Coos Bay. A strong 

 tide sets into the bay and floating specimens may be readily carried 

 for miles in either direction. Tlie determination of the lineage of such 

 forms constitutes a real problem which, in each case, wherever it may 

 arise, can only be solved by experimentation. In a jilace like Coos 

 Bay, the demonstration could fairly easilv be matlc. 



