324 SCIENCE PROGRESS 



of lines of silk which sometimes helped it to catch its food, its skill as a retiarius 

 was not great. I have seen it take perfectly in its "jaws" a fly flying at some 

 speed towards it, as prettily as a cricketer making a slip catch. Another point of 

 interest was its great voracity. It would suck absolutely dry three or four blue- 

 bottles {Call, erythrocephald) a day and every day, while a large Tegenaria 

 fiarietina, Fourc, would not eat more than a quarter of that amount. 



This Pisaura, with several others, practically confirmed my suspicion that a 

 spider tends to bite a captive insect in the most vital part, the thorax. As often as 

 not, the spider at its first rush secures the leg of its victim, and it invariably 

 follows this up by biting the thorax. I have also seen a spider which had 

 pounced upon a C. erythrocephala definitely turn the struggling insect over and 

 bite it in the thorax from beneath. And a House Spider that I saw tackle a 

 large Pronuba, or Yellow Underwing, approached the moth from behind and 

 contented itself with putting its claws on to its wings, until it was in a position to 

 seize it by the thorax. I must mention, however, that I was entirely at fault in 

 comparing this action to that embodied in Dr. A. H. Cooke's investigation on the 

 mussel. Dr. Cooke's results showed precisely the opposite, viz., that Murex 

 tends to strike the mussel practically anywhere. 



With regard to the action of spiders when thrown on the surface of water, 

 a more extended series of experiments shows the following results : 



i. Vagabond spiders can run on water as easily as on land, 

 ii. Sedentary spiders unaccustomed to run, struggle hopelessly and make no 



progress, 

 iii. Sedentary spiders accustomed to run on their webs are either light enough 



to run off, or else can " swim " off like Tegenaria atrica. 



A curious action of male spiders, and I believe of male spiders only, is a 

 sharp twitching of the abdomen, or jerking it down on to the web. No silk can 

 be seen to be secreted, and a male spider on the web of a female does it 

 whenever it stops moving, but never more than once at a time. This habit 

 was recorded by F. M. Campbell {Jour. Linn. Soc. xvii. 1883), who describes it 

 as a sign of impatience. I cannot, however, help thinking that it must possess 

 some physiological rather than psychological significance. I open admittedly a 

 controversial subject, and one in which each is entitled to his own opinion, for 

 what it is worth, when I express my belief that no spider ever felt impatient. 

 It is hardly probable that, even supposing such a mental state possible, an animal 

 whose life was so largely spent in waiting for the chance blundering of an insect 

 into its web could retain such a characteristic, nor do I believe that a spider could 

 become impatient any more than it could feel delighted or love-sick. We cannot, 

 however, by any means get inside the spider's mind, and the final court of appea 

 must remain, as with Aristotle of old, the judgment of the educated man. 



SOME HISTORICAL REFLECTIONS ON CANCER (Harold F. 

 Cooke, M.A., University, Durham). 



It will probably, I think, be allowed that ancient history and ancient literature 

 may throw some light upon modern disease. 1 While I cannot, unfortunately, 

 pretend to more intimate knowledge of the ills of the flesh than the generality of 

 men are the heirs to, I desire in these papers to put forward some reflections on 

 the subject of cancer. 



1 I may, perhaps, refer more especially to my friend Mr. W. H. S. Jones's 

 little volume on Malaria : A Neglected Factor in the History of Greece and Rome. 



