1885.] G. M. Giles— On Prothalhis of Padina Pavonla. 83 



The President expressed his own regret at the death of Dr. Banerjea, 

 and the sorrow the Hindu community had felt at the loss of one of their 

 leading members who was distinguished for his literary attainments and 

 public services. 



The President reported that Mr. Pargiter had resumed his duties 

 as General Secretary, and proposed a vote of thanks to Major Water- " 

 house for his services as General Secretary ; the vote was carried un- 

 animously. 



The following paper was read : — 



Natural History Notes from H. M.'s Indian Marine Survey Steamer 

 Investigator, Commander Alfred Carpenter, R. N., Commanding. — 

 No. 3. On the Prothallus of Padina pavonia. — By G. M. Giles, M. B., 

 P. R. C. S., Naturalist to the Indian Marine Survey. (Postponed from 

 previous meeting.) 



f Abstract.) 



The author in this paper describes certain oval deep-green bodies 

 about 5 mm. in diameter, which he had found growing on the fronds of 

 this common sea- weed, and scattered in clusters in immense numbers 

 on the surrounding rocks ; and arrives at the conclusion that they 

 represent the prothallus or sexual stage of the plant — the stage usually met 

 with being asexual and answering to a fully formed fern. Only one kind 

 of spore is produced by the asexual plant, alternating with tufts of jointed 

 hairs which the author regards as paranemata in opposition to Agardh, 

 who appears to have mistaken these structures for antheridia. In many 

 instances very young fronds of Padina were observed sprouting from the 

 circumference of the prothalloid bodies, which in these cases had 

 already begun to shrivel and decay. The minute structure of the pro- 

 thalloid bodies is described in detail. The tissue containing abundant 

 chlorophyll which gives to the bodies their beautiful green colour, is 

 encased in a coating of white transparent cellular substance thicker 

 and more opaque on the lower than on the upper surface, where it 

 permits the subjacent green tissue with its marbling of darker green 

 to be seen through it. This outer or peripheral tissue is composed 

 of a network of stellate cells with anastomosing tails, resembling the 

 adenoid tissue of animal histology, and enclosing in the meshes of its 

 lower part a number of opaque spherical bodies, which appear to 

 consist of one or more layers of minute colourless rods radiating from 

 a common centre, so that their entire periphery is beset with minute 

 blunt spines. It encloses a number of tubular bodies, which are 

 supported by bands springing therefrom, the interstices being filled 



