192 



SCIENCE. 



[N. S. Vol. XVII. No. 422. 



be provided with a windmill to furnish run- 

 ning salt water for aquaria and a tank to 

 retain rain water. The laboratory proper 

 should be a large, well-ventilated wooden 

 building having a good north light. No bet- 

 ter room has yet been devised than that of the 

 Newport laboratory designed by Alexander 

 Agassiz, although the ventilation of a trop- 

 ical laboratory should be provided for with 

 special care. 



A small working library and sleeping rooms 

 should be attached to the laboratory, and the 

 kitchen and alcohol storage sheds should be 

 in small separate buildings. Six thousand 

 dollars would be required to construct the 

 laboratory and its accessory buildings. 



A seaworthy launch at least 55 feet in 

 length and of light draft would be required. 

 This should be provided with sails, auxiliary 

 naphtha for power, and soxmding and dredg- 

 ing reels. Such a launch is necessary, in or- 

 der to study the life of the Gulf Stream itself 

 and of numerous reefs at the Tortugas and 

 its neighborhood. It should be capable of 

 making the journey to and fro between Miami 

 or Havana and the Tortugas. 



The time has come -when American men 

 of science should awaken to the fact that we 

 have at our very door a tropical fauna far 

 surpassing in richness that of Naples. With 

 our great wealth and many able and energetic 

 workers, we should begin to perform the task 

 for science which is being so ably done at 

 Naples. The great monographs of the Naples 

 Laboratory should be our incentive to do 

 even more and better things in the develop- 

 ment of knowledge concerning the marine 

 life of tropical America. 



Alfred Goldsborough Mayer. 



mtrseum of the brooklyn institute of 

 Akts and Sciences. 



egg-laying in gonionemus. 

 In a preliminary report on the life-history 

 of Gonionemus (Jour. Morph., Vol. XI., p. 

 494) I stated that the cause of deposition of 

 eggs was due to the withdrawal of light, as 

 the animals could be induced to deposit the 

 eggs almost any time of day by placing them 

 in the dark for an hour. The next year 



(1896) some experiments were made with col- 

 ored light to find if egg-laying could be 

 brought about in more than one way and 

 thus get nearer the cause. As I was not able 

 to continue these experiments and some one 

 else may be in position to do so, I give the 

 substance of a few notes made at the time 

 and the conclusion. The medusse were ex- 

 posed in a blackened box, one end of which 

 was closed with a sheet of the desired color 

 glass. 



First some medusae were exposed to yellow- 

 orange light for one hour. The sun was not 

 shining into the box; no eggs were deposited. 

 These were then exposed for one hour to blue 

 light (cobalt glass) and eggs were deposited; 

 they were abnormally slow in segmentation. 

 Next some of the animals were exposed under 

 darker orange glass for two hours and no 

 eggs were deposited. This and a control set 

 were then put in the dark for one hour and 

 in both cases eggs were deposited normally. 

 Two females and a male were exposed under 

 blue glass for one hour. The sun was shining 

 through the glass and it was, therefore, lighter 

 than in the other exposure under the blue. 

 No eggs were deposited within the hour. 



Sixteen females and one male were exposed 

 under dark ruby glass for one hour and ten 

 minutes, the sun shining through the glass; 

 no eggs were deposited. In two other trials 

 under the ruby glass when the sun did not 

 shine into the box eggs were deposited. Im- 

 mediately after the first exposure to red, 

 above, the animals were placed under blue 

 glass and left for one hour and fifteen min- 

 utes, and still no eggs were deposited. It 

 took over one and one half hours' exposure 

 to darkness before extrusion took place. 

 Whether the previous exposure to ruby light 

 had a retarding effect or not was not deter- 

 mined. The conclusion drawn was that the 

 colors were not effective as such, but merely 

 as they obstructed the light. It was also 

 found at that time that the gonads removed 

 from the animal deposit the sex products just 

 as well as the intact animal. 



L. MURBACH. 



Detroit, Mich. 



