336 THE SPIDERS. 



according to Moggridge, to prevent the sand blown about 

 by the violent sea-winds from penetrating into the nests. 

 During winter the opening is wholly and continuously woven 

 over, and it is very well possible, or probable, that the process 

 of reopening such a warm covering in the spring, after this 

 opening was three quarters completed and was large enough 

 to let the spider pass out, may have long ago awaked in the 

 brain of some species of spider the idea of making a permanent 

 and movable door. But from this to the practical construc- 

 tion of so perfect a door as we have learned to know, and 

 even to the building of the exceedingly complicated nest of 

 the JV. Manderstjernce, through all the gradations which we 

 already know, and which doubtless exist in far greater 

 number, is no great or impossible step ; and the truth of 

 the old Linnrean maxim, Natura non facit saltum (Nature 

 takes no leaps), is here again proved in the most striking 

 manner in favor of the theory of evolution. As the animal 

 in common with the whole organised world is physically 

 developed, transformed and improved, so it is also developed 

 psychically to that height whereto the nature of its 'organisa- 

 tion and life conditions enable it to reach: it is only the 

 extreme shortness of our experience which does not distinctly 

 prove this to us, and allows us to think that all is standing 

 still, just as on account of its vast distance the heaven of 

 the fixed stars is to us a picture of an eternal remaining 

 rest, while, in reality, all is movement and change there. 

 So can the intellectual and physical life of animals now 

 only be rightly understood to-day by those who seek and 

 find the key of the knowledge of its existence in the 

 present in the many millions of years reckoned as its past, 

 and thereby utilise as ladders the vast mass of transitions 

 and gradations present also to-day. He who does not know 

 or does not understand this key for the solution of the great 

 enigma, he stands to put it somewhat drastically with 

 regard to this question, as the ox on the mountain, and can 

 only arrive at the absurd opinion, despising all facts, which 

 was maintained, for example, by Professor John Huber, of 

 Miinchen, in his articles on scientific questions of the day 

 (Supplement of the Allgemeinen Zeitnng of July 14th, 1874), 

 where he alleged that animals make no progress, that they 

 discover nothing, that they build their nests as at first, that 

 they indeed gain experience, but cannot impart their know- 



