PART III-EARLY LIFE AND DISTRIBUTION 



OF SPECIES. 



CHAPTEE VIII. 

 COCOON LIFE AND BABYHOOD. 



I. 



THE tyro in arachnology experiences his first and greatest difficulty in 

 the attempt to separate between the mature and immature spiders collected 

 by him. There are resemblances between the young of various 

 _ u an species, particularly of the same genera ; and the differences be- 

 tween the young and the adult of any one species are, in certain 

 cases, so great as to produce confusion. In point of fact, except for pur- 

 poses of special study in life economy, young spiders are not worth collect- 

 ing or retaining in a collection. The valuable specimens are only those 

 which are mature. 



Now, it must be remembered that spiders do not undergo a metamor- 

 phosis a fact which is continually forgotten because of their classification 

 with insects by the earlier writers, and the frequent treatment of them 

 under Entomology even at the present day. Certain orders of insects, as 

 the Lepidoptera, undergo a complete metamorphosis. The butterfly ar- 

 rives at maturity through the well marked stages of the eater- 

 Spiders pillar and chrysalis. Other orders, as the Orthoptera locusts 



Without -, , r in 



M , and grasshoppers, for example have an incomplete- metamor- 



phosis, phosis. But a spider is a perfect animal from its birth, and 

 only requires the general growth and strengthening of its mem- 

 bers, together with the development of the sexual organs, to complete its 

 maturity. 



This maturity is reached after several successive moultings of the skin. 

 An important outward structural change takes place at the final moult, 

 at which time male spiders get their complete armature of spines, bristles, 

 and hairs, according to their species. Moreover, the last" or digital joints 

 of the palps, which, to quote the language of Cambridge, 1 have been up 

 to that time tumid and homogeneous, break up into the digital joint, so 



1 " Spiders of Dorset," Introduction, page 26. 



(206) 



