February, 1922.] 



The Canadian Field-Naturalist 



37 



bird tenants has been modified through constant 

 human association, the cat finds profitable and 

 easy hunting. We are told that cats can be train- 

 ed not to attack birds, but my experiences have 

 only served to strengthen my doubts of this 

 assertion and, after my pet cat, who was sleek 

 with good feeding, had clawed her way up the 

 side of an out-house and dragged a sitting Moun- 

 tain Blue-bird from her nest, I gave up trying to 

 educate puss as a hopeless task and decided that 

 she was a luxury I could not afford. However, 

 their destructive qualities are receiving full 

 measure of publicity in these days of enlightened 

 bird-protection, and it is a healthy sign of progress 

 when two of the major game associations of 

 British Columbia propose that the cat be controll- 

 ed by a license system. 



The House Wren, in this sanctuary, has proved 

 himself an irresponsible and immoral little vaga- 

 bond. When he first comes in the spring, and, 

 perched on the ledge of my bedroom window, 

 trills a clear bubbling ecstasy of song, it is hard 

 to realize at these moments that many of his 

 ways are evil and that his presence in the sanc- 

 tuary is taboo. But I know him of old. He will 

 beglamour me with his song and his merry ways 

 in the intervals of stufl!ing the bird-houses full of 

 twigs until the entrances are blocked. And then, 

 after he has secured a mate and they have selected 



a bird-house for their housekeeping, and after I 

 have laboriously cleaned out the cock nests from 

 the other boxes and decided to give him one 

 more chance he will repay my forbearance with 

 his usual malevolence. For he wants every bird 

 house and every hole where a nest can be built 

 for his own private use and the rightful tenants 

 will be harassed and persecuted at every oppor- 

 tunity. His dislike of other box-nesting birds 

 is apparently an active instinct and much of his 

 superfluous energy is spent in squabbling with 

 the peaceful Tree Swallows and Blue-birds. 

 Unless he is forcibly repressed, the little ruffian 

 will sometimes enter their nests and pierce their 

 eggs with his sharp bill, apparently in rage and 

 spite, as he does not eat the eggs. For two 

 successive summers I was absent during the 

 early part of the breeding season, and, on my 

 return, found three pairs of House Wrens in pos- 

 session and the remaining seven bird-houses 

 stuffed so full of twigs that the entrances were 

 impassable. It was obvious that the Swallows 

 and Blue-birds required the aid of a human ally 

 to withstand the aggressions of the House Wren, 

 and, as seven or eight pairs of the former are 

 thought preferable to three pairs of Wrens and a 

 litter of twigs in empty bird-houses, such assistance 

 has not been withheld since that time. 



THE FRESH-WATER LEECHES fHIRUDINEA) OF SOUTHERN CANADA 



By J. Percy Moore 



{Continued from Vol. XXXVI, page 11.) 



Hsemopis grandis (Verrill). 



"Blue Sea Lake, Quebec, September 28, 1919. 

 R. M. Anderson. Clinging to keel of boat." 

 One specimen. The vestigeal jaws bear an apical 

 double fold but no trace of teeth. 



"On dead pike (Esox lucius), Rideau River, 

 Ottawa, Ontario, April 6, 1917. F. Johansen." 

 The single example was dissected. The repro- 

 ductive organs present some peculiarities. Both 

 atrium and vagina lie to the right of the nerve 

 cord. The epididymis is unusually massive and 

 I lies along the entire length of the sperm-sac. 

 The much enlarged vagina reaches to ganglion 

 XVI, the posterior half being greatly inflated and 

 the much crowded and folded anterior half being 

 only one-third to one-eighth its diameter. 



"Rideau River, near Ottawa, Ontario, May 15, 

 1918. P. Blakeley." An immaculate individual 

 with a distinct and continuous marginal yellowish 

 stripe. 



"Rideau River, Ottawa, Ontario, October 12, 



1919. W. K. Bentley." A very pale specimen, 

 smoke-gray above, ashy-gray below, with a rather 

 distinct yellowish marginal stripe. 



"Rideau River, Ottawa, Ontario, middle of 

 May, 1919. E. M. Kindle." One, unspotted. 



"Kapuskasing River (Moose River), Ontario, 

 July 8, 1919. C. E. Johnson." A young one 

 16.5 mm. long. Dorsum smoke-gray thickly 

 speckled with irregular black spots sometimes 

 confluent. Venter light gray, immaculate except 

 near the margins, where there are a few black 

 spots. 



"Cross Lake, Manitoba, summer, 1919. F. J. 

 Alcock." One. 



"Probably from lakes in Alberta and Saskat- 

 chewan, 1894. John Macoun." One, with H. 

 marmoratis. 



ERPOBDELLID^. 

 Erpobdella punctata (Leidy) 



"Elmsdale, Nova Scotia, July 2, 1920, May 23- 

 28, 1921. A. H. Leim." A small example 

 dredged in shallow water at each station. 



