June, i 9 o 5 .] Packard : Color in a Flower Spider. 91 



That butterflies may occasionally be seized and destroyed by these 

 voracious spiders is farther proved by Mr. Firmen * quoted by Mrs. 

 Peckham. He once saw two butterflies " in the clutches of a spider," 

 and on another occasion "witnessed the actual capture of a small 

 blue butterfly {Lyacnestes') by a white spider of the same genus" 

 ( Thomisus). 



Returning to the subject of a change to rose-red, which I have 

 not myself observed, Firmen mentions seeing at Cape Town a species 

 " of the exact rose-red of the flowers of the oleander ; and to more 

 effectually conceal it, the palpi, tops of cephalothorax, and four lat- 

 eral stripes on the abdomen, are white, according remarkably with 

 the irregular white marking so frequent on the petals of JVertum." 



Rev. O. P. Cambridge f has found Thomisus onus/us pink when 

 upon heather blossoms, and quotes Rev. C. W. Penny to the effect 

 that it is yellow when upon yellow blossoms. 



Prof. Edouard Heckel % has described and illustrated with two colored plates the 

 color variations of Thomisus onustus — a species abundant in the south of France. 

 This spider frequents the flowers of Convolvulus arvensis, and is so abundant during 

 the months of August and September that nearly every plant has its spider ; it is 

 evident, therefore, that, in spite of the numerous insect visitors to these flowers, there 

 must be a certain amount of competition for food among the spiders ; this is especially 

 the case if it be true that the spider limits itself almost exclusively to two Diptera, 

 ignoring the other insects. The flowers of this Convolvulus show three varieties : 

 one is pure white ; another pink, with traces of a vinous red externally ; while the 

 third is a paler pink tinged with green externally. These three varieties of the Con- 

 lus are inhabited by three varieties of the Thomisus which correspond exactly 

 in their hues with the flower, with the exception of the one which lives in the white 

 flowers ; this variety of spider has a blue cross on the abdomen, and the extremities 

 of its legs are likewise bluish. Blue, however, may be suggestive of shadow, and 

 not render the animal very conspicuous. These three varieties do not embrace all 

 the colour modifications of which the spider is susceptible ; it becomes a dark red 

 when upon the flowers of Dahlia versicolor, which has a similar colour, and yellow 

 when upon the flowers of the yellow Antirrhinum ma/us. 



That I failed to find any bluish individuals is probably due to in- 

 complete observations, since bluish individuals may yet occur in New 

 England. That no pink ones occurred in the flowers of the wild rose 

 examined may be due to the fact that those found by me may not have 



* Protective resemblances and " Mimicry" in animals, p. 4. 

 j Spiders of Dorset. 



{ Bulletin Sc. France et Belgique, XXIII, 1S91. Quoted from Beddard's Ani- 

 mal Coloration, p. III. 



