The Zoologist — August, 1866. 325 



and then the sinking in will cease. It has been tried to place dead insects on the 

 ' firn,' when the body was found to swell up to a soft mass, then to shrink very much 

 and afterwards to decay; afier this the ' firn ' closes itself over it, which does not easily 

 happen with livin<i; insects." Mr. Mliller siif;g;ests that the lumps of peat found in 

 several of the holes were the sediment of the decayed bodies of the insects, perhaps 

 increased in size by dust or tine sand so often carried by heavy gales; and adopts the 

 theory that the holes were formed by the vadiaiion of heat from the insects. 

 Mr. Pascoe did not, however, believe that radiation alone would account for insects 

 sinking to the depth of two feet; he thought that long before they reached such a 

 depth ihey would have exhausted the heat already absorbed, and would be concealed 

 from the sun's ra)s by the imminent snow, and thus be prevented from absorbing more 

 heat. On the Monte More the holes were about an inch in depth. 



Prol. Westwood had observed bees which had been tempted out of the hive by 

 early sunshine to fall on the snow; becoming benumbed by the cold, ihey lay without 

 action, and gradually descended, so far at all events as that the whole of the body was 

 below the level of the snow. 



Prof. Brayley (who was present as a visitor) criticized von Tschudi's explanation of 

 the reason for the insects settling on the ' firn,' and wished to know whence the oxygen 

 was supposed to be derived; he suspected that von Tschudi had in his mind the old 

 and exploded notion that pure oxygen was given off during the melting of snow, or 

 that the water of melted snow contained an extraordinary quantity of oxygen. 

 Insects, however small, would from the texture of their wings absorb heat very 

 readily, and when placed on the snow they would by radiation give it off again, 

 probably with equal rapidity ; the melting of the snow, the formation of a cavity, and 

 the descent of the insect, would be the natural result; but he was not able to account 

 for an insect sinking to the considerable depth of two feet, as mentioned by von 

 Tschudi. He should like to ask Mr. Pascoe whether the diameter of the hole in the 

 snow greatly exceeded the expanse of the out-stretched insect? He imagined it 

 would not. 



Mr. Pascoe replied that the insects, when taken out of the cavities, were wet and 

 limp, and their wings became clogged together, so that he could not speak with 

 accuracy as to their admeasurement ; he thought, however, that the breadth of the 

 expanded wings would be nearly equal to the diameter of the hole. 



The President said that he also had noticed similar holes in the snow when 

 crossing some of the Alpine passes, though at the lime he had not bestowed upon 

 them the attention which it now appeared they deserved. 



The President called attention to a paper by M. Balbiani, published in the 

 'Comptes Rendus,' June 4, 1866, in which the writer propounded a theory that the 

 Aphides are hermaphroditic. According to M. Balbiani's observations, each ovarian 

 tube possesses an enlarged end which contains a group of cells ; one of these, which 

 occupies the centre and is surrounded by the others, is the most important, "car elie 

 rejjresente I'element generateur ou la cellule mere de tons les ovules qui, dans chaque 

 gaine, sont destines a se transformer en embryons;" the peripheral cells nourish the 

 central one ; when the ovule enters the ovarian tube, it possesses a germinative vesicle 

 and spot; the latter soon disappears, and after it the vesicle also; during this time 

 many nuclei become apparent in the surface of the vitellus, and condense round 

 themselves the homogeneous substance of which it consists ; these are the blastodermic 



