SCORPIONS, SPIDERS AND CRABS 251 



an occurrence after pairing is only curious if considered 

 apart from their habits. When the sexual desire is 

 satisfied, their actions would again be directed by the 

 dominant instinct of destruction. 



It is to be noticed that the attack, when made by a 

 female, often immediately follows the sexual union, while 

 in the case where males assume the aggressive it takes 

 place some time afterwards. Mr. Campbell explains this 

 by the supposition that the action of the female, when 

 satiated, would be precipitated by the threatened and 

 unacceptable continued application of the hard, spiny 

 palpus, while the more lasting desire of the male would 

 have to subside before he became directed by another 

 instinct. By that time, other attractions, if not his 

 wandering disposition, would take him away from the 

 web. 



The fact that male Spiders are comparatively rare 

 is perhaps explained by the fact that they are very short- 

 lived ; they probably die soon after pairing — even if they 

 are not eaten ! The snares they spin, it is to be noted, 

 are very imperfect, though curiously enough, when young 

 they make perfect snares on a small scale. 



It will have been noticed, in the course of the foregoing 

 descriptions, that Spiders display a more or less con- 

 spicuous wariness, a cool, deliberate " counting on the 

 cost " in their matrimonial ventures that is often want- 

 ing in such matters in the human race. But, then, the 

 risks involved are more patent, more imminent. Mr. 

 Campbell comments on this intelligent behaviour in the 

 case of the Cellar Spider, remarking that they measure 

 " each other's strength when on the same web by the 

 tension and motion of the threads." 



A word as to the Scorpions. These creatures are near 



