Diigesiella hentzi (Girard). 369 



the outer marks of the lower processes of the endosternite wliere 

 tliey are connected witli the cliitin. The nerves running from the 

 central nervoiis System to the liairs in the sternum may be seen in 

 great numbers on each section, the thoracic ganglion being close to 

 the skin and the nerves short and rather thick. We have in the 

 hairs of Bugesiella sense Organs capable of perceiving the slightest 

 touch and, probably, of distinguishing between various degrees and 

 kinds of touch by means of the various kinds of hair. A light 

 breeze or even the mere breath of one's mouth makes Bugesiella 

 jump. If a cricket but touches the hair covering the leg of Bugesiella 

 with the end of one of its antennae, this touch is sufficient to convey 

 to the mind of Bugesiella the fact of the presence of prey. Touching 

 with a silk thread sometimes produces the same eflfect as the touch 

 of an insect. Bugesiella will try to seize the thread as it does the 

 insect. But if a pencil is used the contact is too rough and Buge- 

 siella goes away, assuming, if further molested, the characteristic 

 threatening position. These experiments show that Bugesiella is able 

 to distinguish between at least two kinds of touch. The light touch 

 awakens in her the association between touch and food and the 

 rougher, between touch and the enemy. That we have here to do 

 with associations and not with mere reflexes we may gather from 

 the different answers to the same Stimulus under different conditions. 

 If Bugesiella is not hungry or if the weather is cold, a cricket or 

 Spider may creep all over her body with impunity. She does not 

 make the slightest attempt to catch it but tries merely to get rid 

 of it by brushing it off with her legs. 



Touch, then, is the main sense of the tarantulas. We should, 

 however, be making a grave error if we would deny to their sense 

 of sight all influence upon their lives. The enemies of the tarantulas 

 are chiefly active by day, quite particularly the "tarantula hawk", 

 Pepsis formosa. If the tarantula were unable to distinguish between 

 night and day, it would expose itself to a great many dangers it 

 avoids by hiding in its hole which the enemy must find and enter. 



Construction of the spermweb and the filling of the 

 palpi with sperm, 



I have observed fifteen times the construction of the spermweb 

 by the male. The observations were made on five different specimens, 

 in each case from the very beginning to the end, and in all fifteen 



