150 Psyche [October 



I have made an attempt, on the basis of these meagre data, to 

 gain an idea of the ecology of Chionea in Nature. What is the 

 biological significance of its living on the snow? Food is appar- 

 ently not taken, hence the quest of food cannot be the purpose. 

 The larval stage can naturally not live on the snow. Consequently, 

 I assume that the ecological significance of the nivicole adaptation 

 is that it affords to these wingless insects an opportunity for the 

 sexes to meet, the considerable distances which may be covered 

 on the snow supplanting in a measure the function of the wings, 

 especially if the insects are aided by the eyes in finding each other. 

 As long as the insects are hidden in the half-frozen ground under 

 the snow, the chances of the sexes to find one another are very 

 remote. However, as soon as fresh snow falls, and the tempera- 

 ture rises (usually for one or two days) to somewhat above freezing, 

 Chionea becomes strongly positive phototropic and negative 

 geotropic. The insects seek the light, climbing up, probably not 

 through the snow, but around tree-trunks, bushes or other places 

 relatively free from snow, and run about, covering considerable 

 distances. After copulation has taken place, the males die, and 

 the females return under the snow where they are protected from 

 extreme cold, depositing the eggs from which larvae may develop 

 in the spring. Possibly, the change to low temperature, as it 

 usually occurs soon after each fresh snow-fall, will be in itself 

 a sufficient cause for the insects, males and females, to return 

 under the snow until the next favorable opportunity. On all 

 of these points new observations are necessary. I wish, how- 

 ever, to call attention to the fact that Lugger in Minnesota 

 (1895) has indeed observed that Chionea copulates on the snow,, 

 in spite of several degrees below freezing in the cases observed by 

 him, and I found my own hypothesis confirmed by his findings. 

 Lugger also observed that the female crawls down through a crev- 

 ice in the snow and deposits her eggs which are described as 

 elongated and yellowish, but which did not hatch. 



It is to be noted in this connection that, according to T. W. 

 Cockle (1914), also Boreus, the other well-known snow-insect, is 

 found to copulate in mid-winter on the snow, as he observed in 

 many instances giving a detailed account of the process; and it 

 would be of considerable interest to know whether in Boreus there 



