1901 ENTOMOLOGICAL SOCIETY. 



judge by the presence of these typically prairie plants and the general perfectly level appearance 

 of the country. 



At Sarnia there is a great deal to interest the entomologist and Prof. Macoun found a great 

 number of plants not recorded from Canada, among which was a grass new to science. The 

 most striking thing in the insect line was the abundance of Papilio Cresphontes. Any number 

 <;ould have been taken but I had no space in either my bottles or boxes for anything but 

 Orthoptera and dragon-flies. Another interesting butterfly found here and both at Chatham 

 and Leamington was Pieris protodice. At the two latter places it is the common white butter- 

 fly, rapae being only occasionally seen. At Sarnia both are common but protodice is much the 

 more predominant, while further north only rapae is seen. 



This re-appearance of P. protodice after its apparent replacement by P. rapae strikes one as 

 being quite remarkable, and it seems to confirm Mr. Moffat's opinion, expressed in the Twenty- 

 fifth Annual Report of the Entomological Society, p. 61. He refers to the rapidity with which 

 this change was brought about and regards as very improbable the theory that the disappearance 

 of P. protodice has resulted as a conseijuence of the struggle for existence and the survival of 

 the fittest. Mr. Moflat's idea is, briefly, that the two forms are races of one species, which on 

 being brought together have interbred ; the result being the persistence of the characteristics of 

 the stronger race, rapae, and the suppression of those of the weaker, protodice. But although 

 protodice is weaker, its characters are such as have resulted from its particular environment, 

 such as the climatic conditions and other external influences under which it lives ; and hence 

 these characters must inevitably reappear in time as these same forces are still at work. Mr. 

 Moffat also noted the recent capture of a few specimens of protodice in the vicinity of London 

 and expressed the opinion that it would be common again in time. That it is becoming so seems 

 to be evident from what I have observed in Southern Ontario, whatever the explanation may be. 



Of Orthoptera and Odonata a number of interesting things were taken. Most of tliese were 

 ■captured m a large open stretch of meadow-land, which extends along the St. Clair River be- 

 tween the town and the southernmost point of Lake Huron, where the St. Clau- River leaves it. 

 This stretch of country is under water during the spring and early summer but was quite dry 

 •when I saw it in August, and portions of it were gorgeous with the purple spikes of Liatris 

 spicata, the dense button-snakeroot, making one of the most brilliant floral displays I have ever 

 seen. Several interesting things were found here, notably Orphulella pelidna and Conocephahis 

 ii,ebrascensis neither of which had been taken before in Canada, nor were they met with again 

 during our trip. I also took specimens of the two beautiful dragonflies, Celithemis eponina and 

 0. elisa, the former flying about for the most part near the river where the ground was still wet, 

 the latter being commoner further inland. 



Separating this stretch of meadow-land from the wide beach of the lake is a high ridge of 

 «and dunes wooded mainly with oak, while west of the town of Sarnia is the cemetery, which is 

 also sandy, being much like High Park in character. Both of these localities, especially the 

 latter, will richly repay the efforts of the entomologist. 



Before leaving Sarnia finally the Professor and I crossed the river to Port Huron and thence 

 took the electric railway down the river to Algonac, where we hired an Indian boy to ferry us 

 across to Walpole Id. This is a Canadian island of considerable size and has been set apart as 

 an Indian Reserve. It is an excellent collecting-ground bging for the most part occupied by 

 woods or marshes. Here I saw a great many Papilio Cresphontes, Limenitis disippns, Pieris pro- 

 todice and other butterflies sipping the moisture from the ground near the water's edge. The 

 marshes yielded numbers of Orchelimum longipenne, a green grasshopper only one specimen of 

 which was seen elsewhere, namely at Point Pelee. I was indeed much struck throughout the 

 trip by the fact that these open marshes, though often apparently of the same character and not 

 far distant from one another, may support faunas which are by no means identical, some species 



