Collecting Tools. 



HOW TO KNOW THE SEAWEEDS 



the larger species, and a number of small, screw-cap vials provided 

 with 3% formalin into which small but important specimens may- 

 be preserved from loss or mixing. For removing small plants from 

 rock surfaces a heavy knife or other scaping tool is used, while en- 

 crusting forms which adhere too 

 firmly may be obtained by using 

 a geologist's hammer for cracking 

 off pieces of the supporting rock. 



At the upper levels one will find 

 a number of minute species on the 

 exposed rock surfaces, including 

 various crustose forms which the 

 initiate may overlook unless they 

 are pointed out to him. Lower 

 down, depending upon the amount 

 of exposure to desiccation, one 

 will encounter larger and smaller 



fleshy, clumping forms grading into the densely matted turfs, or heavy, 

 continuous beds of algae at the lowest tide levels. It will not be enough 

 to look superficially over the array of seaweeds to outain a good col- 

 lection, for many species will be hidden under others or will occur only 

 in particular pools, in certain shaded crannies, along the edges of 

 surging tideways, or on the exposed faces of outermost rocks subject 

 to the heaviest surf. Many species will be found growing only as 

 epiphytes or as parasites on other, larger species and should be ob- 

 tained by selection of suitable portions of the host plants. Algal turfs 

 consisting of many species may be brought back as a mass to be 

 examined for their individual constituents in the laboratory. At low- 

 est water level the collector will profit by wading out (in hip boots 

 in cold areas) to look under overhanging rocks, in crannies and pools 

 for the various species which can endure only momentary exposure 

 to the atmosphere. 



When the tide has begun to flow one must hasten to finish the 

 work at low levels before retracing steps inward. With the incoming 

 tide time may be taken to seek special pools and rocky habitats at 

 higher levels which have been passed over before, and there to find 

 additional species. Shaded cUffs subject to spray, the walls of sea 

 caves, the under edges of rocks in tide pools, high, warm pools pol- 

 luted by guano, and other such diverse habitats will all yield dif- 

 ferent species. Even pieces of dead shell or coral may exhibit a green- 

 ish cast indicating the presence of boring green algae. 



After the selection of the attached algae from the intertidal rocks 

 has been completed there is yet another source of specimens which 

 should not be passed by. Especially at times of unfavorable tides one 



