I/O 



THE MUSEUM. 



h 



capture of prey. Some of the Thom- 

 isidfe live on the ground among vege- 

 table debris or beneath stones; others 

 on the trunks or leaves of trees; others, 

 again — and those are the species that 

 have attracted the greatest amount of 

 attention — frequent ilowers, and lurk 

 among the petals on the watch for 

 visiting insects. To this last category 

 belongs the spider fMisumena nepen- 

 thicola) now under discussion, a species 

 which invariably takes up its abode in 

 the pitcher of a North Bornean 

 (Labuanj Nepenthes, perhaps referable 

 to the species described as N. phyllam- 

 phora; in any case, whatever the 

 name of the plant may be, the Misum- 

 ena appears to inhabit exclusively the 

 one species, for although se\'eral other 

 kinds were found growing in the vici- 

 nity, they were never observed to be 

 tenanted by spiders. 



According to that skilled collector 

 and trustworthy observer, Mr. A. 

 Everett, who kindly furnished me with 

 the notes forming the basis of the ac- 

 count here given, the pitchers in 

 question are somewhat elongate in 

 shape, and constricted a short distance 

 below the rim, broadening out again 

 as the bottom is approached, and nar- 

 rowing ultimately to a vanishing point 

 where they join the supporing stalk. 

 Just below the upper constriction the 

 spider spins a slight web, adherent to 

 the wall of the pitcher. This web is 

 not of the nature of a snare or net de- 

 signed to intercept insects, but extends 

 as a thin carpet over a small portion 

 of the conductive area, and enables 

 the spider to maintain a secure hold 

 on its slippery surface. Here it lives 

 and rears its young, no doubt feeding 

 upon the insects which the Nepenthes 

 attracts for its own use, capturing 

 them either as they enter the pitcher, 

 or perhaps after they have fallen in 

 the digestive fluid below. 



So far as procuring food is con- 

 cerned, this spider would seem to be 

 no better off than those of its allies 

 which live in flowers and capture the 

 honey-seeking insects that visit them, 



e.xcept in so far as it is not dependent 

 upon seasonal inflorescence for a place 

 wherein to lurk. But in one very im- 

 portant respect it must presumably 

 score heavily in the struggle for exist- 

 ence — that is to say, in its means of 

 escaping from enemies. 



It is a well known fact that almost 

 all spiders, especially those that occur 

 in tropical and subtropical countries, 

 suffer immense mortality from the 

 relentless persecution of the solitary 

 mason wasps, which at their breeding 

 season scour the country and explore 

 every nook and cranny in the eager 

 search for spiders wherewith to lay up 

 a sufficient store of food for the vora- 

 cious young wasps during the days of 

 their larval existence. From these 

 enemies the flower-frequenting species 

 have no means of escape, except such 

 as is afforded by quiescence, in con- 

 junction with the protective nature of 

 their colors, attitudes, and form. The 

 slightest movement on their part will 

 attract the notice of the quick-sighted 

 wasp, and bring swift destruction upon 

 them. 



Whether or not the mason wasps 

 have the temerity to invade the pitch- 

 ers of Nepenthes in their quest for 

 victims, there is no evidence to show. 

 Possibly long-billed birds thrust their 

 beaks into the insect-trap to extract 

 any living things or organic debris they 

 may contain. At any rate, the ac- 

 count given by Mr. Everett of the be- 

 havior of this spider when threatened 

 with danger points forcibly to the con- 

 clusion that the species is subject to 

 persecution from enemies of some kind 

 or other. This collector found that 

 when an attempt was made to capture 

 them by tearing open the pitcher, the 

 spiders, although very active, never 

 attempted to escape from the mouth 

 of the vessel, but ran down its inner 

 surface, and plunged boldly into the 

 liquid at the bottom, ultimately, if 

 still pursued, retreating to its very 

 base, and burying themselves among 

 the remains of ants, moths, beetles, 



