Atachnida. 7553 



becomes a more important transaction in its life,— it is a condition of 



growth, and is obliged to be repeated with constant regularity to admit 



of the enlargement of the animal. When the larva first breaks the 



egg-case, it is confined within a skin that encloses every part, each 



small cilia is bent, and every large one retracted within itself, like 



the draw-tubes of a telescope; this skin it shakes off within a few 



hours, or perhaps less. A few days and the process is again repeated, 



and probably, at intervals of about the same or a constantly 



increasing duration, is continued for some months. I say probably, 



because no effort has yet succeeded in keeping the larva through the 



earlier stages of its existence. The changes with each exuviation 



are very inconsiderable, but a certain amount takes place at every 



stage, and the animal loses the eccentric form of its youth and 



gradually acquires that of the parent crab. It is after it has arrived 



at the matured form that observers have been most successful in 



seeing the flaying process voluntarily carried on. 



Reaumur was the first man who told us how it was done ; he saw a 

 river crayfish {Astacus Jluviatilis), the ecrevisse of the French, 

 struggle itself out of its skin. There is a charm about being the first 

 to observe a fact ; it is like starting in the race before one follows, and, 

 starting first, keeps all others in the same line behind. Since 

 Reaumur watched the crayfish, others have done the same as oppor- 

 tunity has occurred, and told us how the crab, the lobster, the shrimp, 

 and the lower forms of Crustacea, free themselves from their coats. 

 Couch, Gosse, Sir John Dalyell and Dr. James Salter have each 

 written upon the subject, and 1 have watched them also. Vide An. 

 Nat. Hist. 1849. 



(To be continued.) 



Notes on Spiders captured in 1860. 

 By the Rev. O. P.-Cambkidge. 



An excess of moisture seems to be less prejudicial to spider-life 

 than an excess of drought; and again, moisture is less hurtful to 

 spiders than to insects in general ; and so, while last season was so 

 barren a one to entomologists, I have but little reason to be dissatis- 

 fied with the results of my researches in Arachnology, having captured 

 and observed fifty-four species that I had not seen before, besides 

 discovering both sexes of several others of which only one sex had 

 hitherto been discovered. 



VOL. XIX. 2 L 



