NOTES AND QUERIES. 14!) 



round and round in her beak. As she was caught young, and is rather 

 undersized, she is very probably weaker than her wild relations, and so her 

 inability to crack the stones proves nothing ; but her desire to do so is very 

 evident. An example of another species of Coccothraustes, the Virginian 

 Nightingale, which appeared and was seen about Bodicote for some weeks 

 in severe weather last winter (1886 — 87), and was at last shot with great 

 difficulty (it was extremely wild and vigilant, and all the guns in the 

 village had been after it for weeks), had, I found on examining it afterwards, 

 been feeding on the kernels of holly-berry stones, which are also very hard. — 

 Oliver V. Aplin (Bloxham, near Banburv). 



MOLLUSCA. 



How does a Snail crawl ?— I suppose Conchologists have oftentimes 

 been troubled by tbis question. Does a snail wriggle along the ground 

 like a worm or a snake? If this were the case we should be able to see a 

 series of wrinkles appearing upon the sole of the foot. Indeed if we allow 

 a snail to crawl on an inverted sheet of glass, so as to enable us to look at 

 it from underneath, we fancy we perceive a faint indication of these wrinkles 

 in the shape of a number of dark bands or waves travelling slowly from behind 

 forward. The general notion is that the mechanism of locomotion in the 

 snail is essentially the same as that in many footless larvae of insects, with 

 the difference that the number of wave-motions produced by the foot 

 is much greater, and that the attachment of the sole to the foreign body is 

 much firmer. As I said, the waves which we recognise on the sole seem 

 to strengthen this view at first sight. However, if we examine the 

 phenomenon more closely, we find that the foot of the snail is intimately 

 attached to the glass, and that the waves do not appear between the sole 

 and the glass, but in reality inside the foot, producing no change of form on 

 its surface. Hence we must look for another explanation. There can be 

 no doubt that the locomotion of a snail, such as Helix aspersa, for instance, 

 originates in the waves which we see gliding along the foot. The animal 

 moves as long as the waves last. As soon as the play of waves disappears, 

 the motion also ceases. In order to obtain an interpretation of the 

 significance of these mysterious waves, a study of the anatomy of the foot 

 is requisite. Simroth is the only Zoologist, to my knowledge, who has 

 carefully investigated the course of the most intricate system of muscles in 

 the snail. He found, in fact, that there is a net-work of muscles in the 

 foot going in all directions. There are horizontal longitudinal and 

 horizontal cross-fibres, vertical as well as horizontal and inclined oblique 

 muscular fibres. After many experiments, Dr. Simroth discovered that 

 the horizontal longitudinal fibres brought about the movements of the 

 foot. These are the extensile muscles. They produce the wave-motion. 

 By their action the sole of the foot is elongated in front, and shortly after 



