LIGHT REACTIONS OF A LITTORAL ARANEAD. 75 



phototropic react to the size of the luminous field or to definite 

 objects in the visual field. 



Our Grammonota probably possesses an image-forming eye, 

 but it is negatively phototropic. Whether it reacts to intensity 

 of the light or to its area remains to be determined. I have 

 made no attempt to decide whether it reacts rather to the light 

 rays than the heat rays, and I was not interested to determine 

 this, for in the state of nature heat and light, so far as they affect 

 these animals, are probably always associated. 



Under natural conditions the masses of eel grass that shelter 

 these spiders would be disturbed only by unusually high tides, 

 perhaps occasionally also by violent winds. If the sun were 

 shining during such a disturbance the spiders, from their negative 

 phototropism, would attempt to run landward, and thus some 

 of them might escape the action of the waves; but it is question- 

 able whether this light reaction would be of any great benefit 

 to them at times when the waves play havoc on the beach. 



From the scattered distribution of these spiders one would 

 suppose they might be readily transported by water. I ac- 

 cordingly made a few experiments to ascertain how sea water 

 affects them. A number were dropped upon clean sea water 

 placed in a glass dish; they were able to stand upon the surface 

 film, but not to run unless there were fine dust particles upon it. 

 But so soon as the water was violently agitated they sank below 

 the surface and were unable to rise again. Therefore they 

 could not long remain upon the top of a wave, but would become 

 quickly submerged unless they clung to some floating vegetation. 

 This is because the body is only slightly pilose. They become 

 quiet after a few minutes of submergence, as though partially 

 suffocated, yet they can withstand submergence for some hours. 

 Thus I kept seven beneath water for five and a half hours, then 

 placed them upon blotting paper to dry, when four revived; 

 and I kept another lot beneath water for sixteen hours, and one 

 of these revived after drying. 



A number were placed in isolated vials, each with a few 

 drops of sea water to furnish the necessary moisture, in order 

 to observe the cocooning, but I was not so fortunate as to see 

 this process. The cocoon is lenticular, snow-white and relatively 



