314 NORMAN E. M'INDOO. 



ducing any effect. Such is not true with Meta. Just as soon 

 as the light strikes their eyes, they run into the dark. If the 

 light is repeatedly thrown on their eyes, they may be turned in 

 any direction and often can be driven into places where the light 

 cannot reach them. 



The following apparatus was used in the laboratory: For the 

 adult Metas, slender lo-inch bottles; for the medium sized Metas, 

 6-inch test-tubes; for the spiderlings of Meta and for Troglo- 

 hyphantes, small 5-inch vials. The closed end and the lower 

 half of each vessel were covered with black carbon paper. The 

 open ends were securely closed with air-tight cork stoppers. 

 One specimen with one or two drops of water were placed in 

 each vessel. In a very short time the water forms a thin film of 

 moisture all over the inner surface of the vessel. This saturated 

 the air in both ends equally. The vessels were then placed 

 on an inclined rack by a south window in order to give each 

 an equal amount of light. Occasionally they were rotated so 

 that the light always fell directly upon the spiders' eyes. At 

 various times the carbon paper was transferred to the cork end, 

 thus throwing the specimen into the light or dark as the case 

 may be. Those that were strongly negatively phototropic 

 never lost much time in finding the dark end, regardless of the 

 number of times the carbon paper was changed. Such individuals 

 often pass into the dark in three minutes. The few that were 

 strongly positively phototropic always changed from the dark 

 end to the light end whenever they were thrown into the dark. 

 Some were thus experimented with for thirty days, but experi- 

 ence taught that their actions were reliable for only the first 

 four or five days. Darkness and cloudy weather had much to 

 do with the final results. Time was counted from the period 

 when first placed in the vessel, and each morning when first 

 observed until 6:00 P.M. each day for four consecutive days. 

 When first placed in the vessels and for a short time after the 

 carbon paper was transferred, they were noticed every few 

 minutes, after that irregularly five times every day. 



The adult Metas were always in the dark end during clear 

 and cloudy weather, and always in the light end when it was 

 dark. The medium sized Metas were ahva\N found in the dark 



