154 JOURNAL OF THE [july. 



Some are employed only in procuring food, the tentacles push- 

 ing the prey, maimed by the nettles, into the mouth. Others 

 produce separating buds, furnishing the principal means of prop- 

 agating the species. But also medusoid gemmae are formed, 

 which swim around, resembling free medusae ; and only after 

 passing through this kind of a larval stage do they settle again 

 to become polypes." 



THE FERN, TRICHOMANES LUCENS. 



Mr. E. B. Grove, in explanation of his exhibit, said : 



*' THchomanes lucens belongs to the Hymenophy/laceiC, or filmy 

 ferns. It has very delicate and translucent fronds, seemingly of 

 a lace-like character. The involucres are goblet, or funnel- 

 shaped, and are formed on the ends of each of the pinnae of the 

 fertile fronds, and at the end of a vein. The vein penetrates 

 the involucre, and, dividing into thread-iike filaments, bears the 

 spore-cases. 



" The specimen was bleached in a solution of chlorinated 

 soda, stained with iodide-green, and mounted in balsam." 



Mr. Grove also mentioned his method of removing air-bub- 

 bles from balsam mounts, viz., employing a very minute alcohol 

 flame, applied to that portion of the slide where the bubble is 

 situated, and, as soon as the bubble begins to expand, following 

 it up with the flame to the edge of the cover. 



SKIN OF THE CHAMELEON, 



Mr. J. D. Hyatt, in connection with his exhibit of the cast 

 skin of the Chauieleon, reviewed the theories proposed in the 

 past to account for the remarkable changes of color accom- 

 plished by the animal. He stated that the skin was covered 

 with minute papillje, conical and hollow, composed of thin 

 scales, which rendered them rather nacrous in structure. 



In the specimen under the microscope the color depended 

 upon the angle upon which the light struck these prominences, 

 and,by swinging the mirror from the extreme right to the extreme 

 left, there would be caused a variation from a dull red to a 

 green. The same result would be attained if the animal pos- 

 sessed the power to elevate and depress the papillae, so that the 



