84 G. M. Giles — On ProtJiaUus of Padina Pavonia. [JtrxE, 



with spherical nutritive cells containing much clorophyll. The tubes 

 are scattered in masses through the nutritive central substance, and in 

 each mass two kinds of tubular bodies are to be distinguished differing 

 markedly in size and in the nature of their contents. Of the two kinds 

 of tubular masses of cells, the smaller contains in its lower part masses 

 of cells, each consisting of an oval mother cell enclosing three daughter 

 cells, the contents of which break up into a number of small spherules of 

 a brilliant carmine colour, which in their turn break up into minute 

 rods of the same bright colour : these the author considers to be 

 antherozooids, the tubes producing them being antheridia. The tubes 

 of the other kind are larger and are usually found close to the smaller 

 kind, being commonly enclosed in the same sheath of small-celled 

 tissue. Their lining is usually much thicker than that of the smaller 

 or antheridial tubes, being ordinarily composed of two layers of larger 

 cells. The greater part of their length is as a rule filled with mother 

 and daughter cells, differing from those of the antheridia in containing no 

 coloured spherules or rods and in their more granular contents. Their 

 mode of production is described : a lining cell grows out into the lumen 

 of the tube producing a string of cells which curls round on itself for 

 a turn and a half ; and the oldest cell in the middle of the spiral divides 

 into daughter cells. These larger tubes are considered to be archegonia. 

 Fertilisation, the author surmises, is effected by the breaking down of 

 the ripe antheridial and archegonial tubes and the consequent mingling 

 of their contents. 



Mr. Wood-Mason regretted that the author of this interesting paper 

 had not had an opportunity of thoroughly tracing the development 

 of the tubes which he considered to be of the nature of archegonia, 

 and expressed the opinion that the hedgehog cells were degenerated 

 chlorphy 11- containing spherical cells, rather an ulterior stage in the 

 development of the spore-like contents of the larger tubes, and that the 

 layers of transparent rods giving to the bodies in question their spiny 

 appearance were probably crystals of carbonate of lime. 



The paper will be published with illustrations in the Journal, Part 

 II, for the current year. 



