84 



C.M.Tracy, of Lynn, exhibited some of the specimens 

 of plants collected by him and others during the ramble. 

 He noticed at some length, the influence of submersion in 

 water upon the developement of leaves ; the effect, in gen- 

 eral, being to hinder the production of parenchyma and 

 cause the leaf to remain either deeply serrated and lobed, or 

 else cut into teeth like a comb, and reduced to almost a 

 mere skeleton. In illustration, such instances as the Water 

 Ranunculus, the Mermaid Weed, and the Featherioil, were 

 cited. He also drew attention to the Umbelliferous Family 

 of Plants, some members of which are poisonous, while 

 others have aromatic and useful qualities. It is important 

 to distingiiish these readily, and one of the safest and sim- 

 plest rules is, to reject all that grow in moist grounds. This 

 is, in general a good rule, but there are a few important 

 exceptions ; as for instance, the Poison Hemlock, wholly 

 found on high land, yet very deadly ; and the Angelica, a 

 native of the meadows, though perfectly innocent. 



Dr. George Osgood, of Danvers, enumerated the results 

 of his botanical search and commented thereon. He cited 

 Lady's Slipper, (^Ci/pripedium Acaule) Cucumber Root, 

 (^Medeola) Huntsman's Cup, (^Sarracenia) Wild Cranes- 

 bill ( Geranium') and many others. 



F. W. Putnam, of Salem, spoke of a few species of insects 

 taken along the road from the station, and further, by re- 

 quest of the chair, as to the locomotive machinery of fishes. 

 Though fish have nothing more than fins and tails for pro- 

 pulsion, yet these are used, so far as they go, precisely in 

 imitation of the limbs of the higher animals. The mode of 

 doing this varies ; some nse the fin like an oar in sculling a 

 boat, striking square against the water ; others, as the Ba- 

 listes and Pipe-fish give the vertical fins a wavy motion, 

 simulating the action of a screw propeller. Still a third 

 class, living close on the bottom, use their pectoral fins 



