242 THE COURTSHIP OF ANIMALS 



genital aperture of the female, and their contents dis- 

 charged for the second and last time. This is the critical 

 moment of the Spider's life, and it is noteworthy that it 

 should occur now, instead of at the moment of the dis- 

 charge from the body. The ejection from the palpal 

 organ is effected by means of a fibro-elastic bag, in its 

 normal, collapsed, state spirally disposed round the base 

 of the bulb which contains the sperm tube. Immediately 

 preceding copulation this elastic bag or " haimatodocha " 

 becomes turgid with blood, and it is probably the pressure 

 thus exerted on its base which affords the final fury of 

 desire without which, indeed, one might well imagine the 

 necessary courage for copulation would never be raised, 

 at any rate, in the case of some species. 



Strange as these facts are, the nice adjustment of 

 the instincts for their effectual performance is, by 

 comparison, stranger still. By what subtle sense is the 

 male Spider informed of the importance of the fertilizing 

 fluid which escapes his body ? What prompts him before 

 its escape to prepare a web for its reception .? What 

 prompts him after its deposition to collect it within 

 the palp till it shall be needed ? The least defect in the 

 instincts appertaining to these vitally important acts 

 would mean the extinction of the race. We cannot 

 suppose that the nature of their performance is in any 

 way realized by the performer, and this makes their 

 orderly execution the more wonderful. 



Our knowledge of Spiders under the afflatus of sexual 

 desire has been immensely increased by the long and 

 patient observations of Mr. and Mrs. Peckham. The fact 

 that their investigations were carried on with captive speci- 

 mens, and therefore under artificial conditions both as 

 to environment and the number of individuals placed 



