Stodder.] 132 [February 13, 



Boston Jom'nal of Natural History herein before bequeathed), I give 

 to the Boston Society of Natural History ; I also give to said Boston 

 Society of Natural History in trust the sum of ten thousand dollars 

 to be invested as a permanent fund, the income of which, after deduct- 

 ing all expenses and charges incurred in the management and execu- 

 tion of the trust, shall be forever applied to the purchase of recent 

 shells, of all needful cabinets and cases, and of works relating to 

 shells, or the science of Conchology, and to the expenses of maintain- 

 ing and preserving the collection of shells, the cabinets, cases and 

 books, in good order and useful condition, any balance of income not 

 expended for the purposes aforesaid, to be added to the principal 

 fund." 



Section of Microscopy. February 13, 1867. 

 The Curator in the chair. Fourteen members present. 



Tlie following paper was presented : 



On a Recent Gathering of Diatomaceous Mud from Pleas- 

 ant Beach, Cohasset. By Charles Stodder. 



While on a visit to Pleasant Beach, Cohasset, in the summer of 

 1866, I was strongly affected by an exceedingly offensive smell, which 

 pervaded the vicinity of Kimball's hotel, and was impressed with the 

 fact that the peculiar quality of the odor was the same as comes from 

 a bottle of decaying marine diatoms. The smell Is well known to all 

 visitors and residents of that favorite watering place. I easily found 

 the locality where It originated, the marsh directly In the rear of the 

 Minot House. This marsh Is separated from the bay merely by the 

 strip of sand and pebble beach, on which the Minot House stands. It is 

 covered with water at spring tides. The tide water has access to the 

 marsh by a channel about a mile distant from the Minot House, and 

 must have a course of nearly two miles to reach the place. 



A friend procured for me a bottle of mud from the marsh, taken at 

 high-water mark, which proved to be composed almost entirely of ani- 

 mal and vegetable matter, alive and dead. The origin of the smell was 

 now fully explained by the decomposition of the organic matter. 

 The animals were mostly infusoria, and the vegetables, roots and fibres 

 of grasses, and diatoms. The only inorganic material was a few 

 grains of sand, evidently carried Into the marsh from the beach by 

 the wind. 



