o46 J. G. WALLER ON PARASITIC VEGETABLE ORGANISMS. 



of this, and about 6J miles S. of the " Inner Gabbard," is the 

 " Galloper," about 3 J miles long, and generally similar to the two 

 others in diameter and depth of water over them at low tide. Al 1 

 three have a certain parallelism to our coasts. The depth of 

 soundings between them runs to 14 and 16 fathoms. 



The character of all these sands is the same ; so much so that, 

 on microscopic examination, no one could distinguish between them. 

 Large grains of quartz form the staple, intermingled with calcareous 

 particles derived from shells of molluscs, particularly a small pecten, 

 fragments of polypidoms, echini, &c, &c, all rounded and worn by 

 attrition — a coarse-looking sand, whose calcareous particles rarely 

 exceed -| inch in diameter, and are generally very much less. Not 

 a single fragment of any kind soever occurs of our chalk flint debris. 

 It is quite obvious that none of our coasts, which here belong to the 

 Tertiary system, have had anything to do in the making of these 

 deposits. The specimens of sand obtained for me from the light- 

 ships, were not taken from the shallow surface above indicated, but 

 from a sounding perhaps of 6 fathoms around these shoals. I state 

 systematically all the conditions before I proceed to give you an 

 account of the remarkable parasitic flora found excavating in the 

 calcareous particles. 



It is no new discovery to find parasitic vegetable forms, either 

 to be classed with Algae or Fungi, in calcareous matter. Many 

 observers, both English and foreign, have noted the fact. In the 

 " Transactions of the Microscopic Society' in 1855, is a paper by 

 Mr. Rose, with figures, of excavations in fish scales found in the 

 chalk. Kiitzing, Kolliker, and Pringsheim have also assiduously 

 worked in this direction. 



Mr. H. N. Moseley, the naturalist of the " Challenger" Expedi- 

 tion, has the following note on the subject : " The Corallum of both 

 Millepora and Pocillopora is permeated by fine ramified canals, 

 formed by parasitic vegetable organisms of the same nature as those 

 described by Dr. Carpenter and Professor Kolliker as occurring in 

 the shells of mollusks, &c." He assumes them to belong to the 

 Fungi (" Proceedings of Roy. Society," No. 164). 



Professor P. M. Duncan has an interesting communication made 

 in 1876 to the Geological Society, " On some unicellular Algae, 

 parasitic within Silurian and Tertiary Corals, &c," which shows 

 how remotely in the world's history this phenomenon occurred. It 

 is now my part to state that, in our own seas, the same law pre- 



