Pomona College, Claremont, California 135 



were taken out oi the jar and soon scattered all over the labora- 

 tory. They built their miniature orbs between the legs of chairs, 

 on the lighting fixtures, on the microscopes and in every available 

 plaee. l'he\ would place themselves in the center ol these small 

 orbs and stay there all day. This action o\ the young is quite con- 

 trary to that oi the adult, who does not remain in the orb but in a 

 hiding place near by. The young oi Aranea </(•;//;//</ were found 

 all oxer the top oi a rose fence in little webs. They made them 

 in the top m order 10 get the greatest amount oi light and sunshine. 

 A family oi Aranea was raised in the laboratory windows on the 

 vines. 1 heir actions were not the same as the one raised indoors. 

 rhey remained in a large clump swung from one ol the branches 

 ot the vine and only on bright days did they scatter from this mass 

 to return when the wind blew and it became cold. A hard rain 

 storm came and all the spiders disappeared, but when the sun came 

 out the spiders returned, making little orbs ot their own, but did 

 not go back into a mass. A great main oi these little ones could 

 not have survived the storm, but some must have remained under 

 the leaves and started lite anew as soon as it became warm. 



C ertain conclusions can be drawn in connection with the shape 

 ot the coo- case, the methods of emerging, and the actions upon 

 emerging, ot the immature spiders: 



1. All the coo cases ot a certain species ot spiders were found 

 to be exactly the same. There were la roe numbers of the coo cases 

 ot Aranea collected, and none varied in either shape, texture, or 

 method ot building. The only variations found'were in size and 

 color. The colors varied from light to dark brown. 



J 1 . The methods ot emerging, the length oi time and actions 

 upon emerging varied only according to the weather conditions and 

 situations, so the same statement nun apply to them as to the shape 

 ot the ego case. 



In a genera] collection a great many specimens taken are im- 

 mature and very hard to determine on account ot the undeveloped 

 sexual organs, and the differences in color pattern between the im- 

 mature and its adult. It has been the aim of the writer to watch 

 the changes in the color development and color pattern oi certain 

 well-known species ot la roe families in order to find some way in 



