ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 613 



a forward stroke, the large chclte widely outstretched and held hori- 

 zontally, the creature feeling its way with them. They only feed at 

 dusk or at night. The prey is seized by the left chela, and at the 

 same moment the stiug is swiftly brought over their head and the 

 victim pierced with it. The short chelicerse are then inserted into 

 the soft substance of the prey and the nutriment brought to the mouth 

 by alternate movements of the right and left chelicerse. The combs 

 or pectiniform appendages ordinarily do not appear to possess any 

 special sensitiveness, but they may possibly become more so during 

 the breeding season. The well-attested statement of the suicide of 

 the scorpion when surrounded by a ring of red-hot embers, may perhaps 

 be explained by the fact of some individuals accidentally lacerating 

 themselves with their sting when half suffocated ; Professor Lankester 

 having seen a scorpion under the influence of chloroform vapour 

 make repeated blows with its sting in the forward direction straight 

 above its head until the top of the sting caught under the free 

 projecting margin of the posterior region of the cephalic shield. 



The body of Eascorpius is kept close to the ground, the legs 

 extended on either side, the tail being dragged behind with the 

 slightest upward curvature only, or one to the right or left. In 

 fighting one another the large chelre were used but never the sting. 

 In stinging their prey they do so with great deliberation, the slowness 

 of the process being perhaps due to the fact that the poison-glands 

 have to be compressed by their proper muscles, and the poison 

 squeezed out of the lumen of the gland after the stiug has pierced the 

 prey. 



Nest-forms of the Furrow Spider.* — Dr. H. C. M'Cook has 

 observed that some of the orb-weaving spiders have a marked tendency 

 to vary the forms of their nests. The spinning-work of spiders may 

 be classified as (1) the snare, spun for the capture of prey; (2) the 

 enswathment, by which insects are disarmed and prepared for food ; 



(3) the gossamer, used for purposes of aqueous or aerial locomotion ; 



(4) the cocoon, spun for the propagation and protection of the species ; 

 and (5) the nest, which is a domicile more or less elaborate and per- 

 manent, within or under which the araneid dwells for protection 

 against enemies and weather-changes. As a rule the great groups of 

 orb-weavers differ from each other and agree within themselves in 

 the characteristic form of nest. The form prevailing in each family 

 is substantially the same ; each species appears to adhere quite 

 steadily to one characteristic form ; but there are some marked vari- 

 ations in the habit of certain species, the most decided of which have 

 been observed in the case of Epeira strix, the furrow spider. He 

 gives some examples of this. 



The ordinary nest when domiciled in the open field or wood is a 

 rolled leaf. A second form varies from the rolled-leaf nest in having 

 the edges of two adjacent leaves bent towards each other and lashed 

 together on the exterior at the juncture by silken cords and on the 

 interior by adhesive tissue web. An oval opening is left at the united 



* Proc. Acad. Nat. Sci. Philad., 1882, p. 97. 



