NATURE'S CALENDAR 



205 



So they drift by us through the bright 

 autumnal weather, leisurely by day, hur- 

 riedly at night, wave after wave, follow- 

 ing the turning of the leaves till they 

 come to the still verdant vegetation of 

 tropical lands, and can settle down to six 

 months of pleasure and plenty. 



September is the birth-month of many 

 of the North American snakes, especially 

 of the venomous species. The crotaline 

 snakes mate in March in the Gulf States 

 — later, of course, in the North, but im- 

 mediately after they come out from their 

 winter-quarters. This is true of all the 

 rattlesnakes, moccasins, and copperheads, 

 and also of several other non-venomous 

 serpents. In September their young are 

 born from egg - like envelopes retained 

 within the mother's body until the em- 

 bryos have been perfected and are suffi- 

 ciently active to tear their way out of the 

 case, almost as soon as they are voided 

 into the world, when they begin at once 

 to look out for themselves. The ordinary 

 number produced at a birth by the rattle- 

 snakes and their kin is six or seven, each 

 about seven inches long. 



Other snakes that are ovoviviparousand 

 bring forth their young in late August or 

 September (according to latitude and sea- 

 sonal temperature) are the various garter, 

 striped, or ribbon snakes {EntcEnia and 

 Storeria), and the water-snakes {Tropz'do- 

 notus). All these produce from live to 

 seven young only — very few, as compared 



September 16 



September 17 



