228 UPLAND AND MEADOW. 



up a handful of mud from the bottom of the meadow 

 ditch, and let it pass through a fine sieve, there will 

 probably be left a few white or whitey-brown little mol- 

 lusks, that I can best describe in a general way as baby 

 clams. Certainly, as compared with a hard-shelled ma- 

 rine clant or qnahog, these little fellows from the meadow 

 ditches are very babyish in size. They vary from about 

 one fifth to one quarter of an inch in length, and a little 

 less in breadth. We might live for a century on the 

 very bank of a ditch, yet never see one, so secluded do 

 they keep themselves. It is to be hoped they enjoy life ; 

 but how hard it is to realize that such creatures are con- 

 scious. 



There are two genera of these little baby clams, called 

 Pisidium and Sphoerium, the former having one siphon, 

 the latter two. To the untutored eye they look much 

 alike, and the conchologist must be questioned, if you 

 would know more about them. 



August 2. — I am puzzled to know how the law of 

 evolution operates in regard to the various utterances 

 of birds. Yesterday a pair of chipping sparrows were 

 greatly excited over the departure of their third brood. 

 These little birds were fairly strong on the wing, and 

 able to fly promptly, even from the ground to branches 

 high overhead. Yet the parent birds were not satisfied, 

 and, by a series of chirps and cries of alarm, which every 

 bird-eating animal could readily interpret, they invited 

 every snake, mink, weasel, and other foe of birds to 

 hasten to the spot. Most snakes and certain mammals, 

 and probably sparrow-hawks, are attracted by these 



