crober 



XXXVI 



OF all the creatures that inhabit the heavens above or 



the earth beneath, or the waters under the 



earth, there are none whereof I am conscious of 



more profound ignorance than the Arachnida, or Spiders. 



Yet these are animals of so much character and so varied, 



their ingenuity is so versatile and so consummate, that I 



can conceive no more fascinating and absorbing branch of 



study than concentrated research into their structure and 



habits. 



The sub-class Arachnida forms but a link in the vast 

 group Arthropoda, connecting the Myriapods or Centipedes 

 with the Crustaceans ; yet each of the seven orders com- 

 posing that link would suffice for the entire life-work of 

 any student, no matter how diligent. To realise this it is 

 only necessary to call to mind that these seven orders 

 embrace such a diversity of creatures as the Acarids or 

 Mites, including some of the most odious human parasites, 

 such as the too-familiar harvest bug and Sarcoptes scabiei, 

 the cause of the loathsome itch, as well as the dreaded 

 scorpions, the true spiders, and the curious whale-ticks 

 and other marine parasites. The labours of Dujardin, 

 Claparede, and Siebold upon the mites, of Dr. Dohrn upon 

 the Pycnogonidea or sea-lice, and of Hermann, Latreille, 



