parasitic within recent Madreporaria. 



239 



were normal to the shells, others were the product of " Confervse, 

 Spongida, or of minute boring animals." 



In 1851 Mr. C. B. Eose, F.Gr.S., found minute tubular borings in 

 fossil and recent fish-scales ; and he published his admirable and short 

 researches in 1855, illustrating them with great care and truthfulness. 

 He noticed that it required a magnifying-power of a ^-inch-focus object- 

 glass to trace the course of the tubes ^^^ith any degree of distinctness ; 

 and he pointed out that their minute diameter of jtkTo ioto ^^^^ 

 distinguished them from the results of boring sponges. Mr. Eose did 

 not attribute the tubes to Confervee, but to the operation of "infusorial 

 parasites"*. 



In 1858, C. Wedlt contributed a paper on the subject of these canals 

 in shells. He described and dehneated them; and some of his drawings 

 agree remarkably with those of Mr. Eose. He carried the examination 

 of his specimens much further. He investigated the parasitic canals in 

 recent shells and in fossil Gasteropoda, Biyalves, and Brachiopoda, dis- 

 covering them even in a Leptceua from the Devonian formation. More- 

 over he exposed a recent shell to the action of dilute hydrochloric acid, 

 and by dissolving the carbonate of lime exposed the vegetable organism. 

 He considered that the parasite was Saprolegnia ferax, Kiitz., which he 

 termed a confervan. He did not examine any corals. 



About the same time, KolLiker+ contributed a paper to the Eoyal 

 Society, which contained notices of his having seen the parasitic tubes in 

 a great many shells. Sponges, Poraminifera, and recent Corals ; but he 

 did not advance further than C. Wedl in their description. He noticed, 

 however, that the parasite was unicellular in its construction, and 

 wrote : — " I may further add that the frequent anastomoses of the para- 

 sitic tubes remind one of the anastomoses observed in the mycelium of 

 some unicellular fungi ; whereas such connexions have not yet, so far as 

 I know, been observed amongst the Conferv^e." He stated that the 

 sporangia were quite of the same kind as those of unicellular fungi, and 

 that it seemed probable " that the parasites dissolve the carbonate of lime 

 of the hard structures into which they penetrate, by means of exudation 

 of carbonic acid, which secretion \^'ould seem to take place only at the 

 growing ends of the fungial tubes, as they never lie in larger ca"\dties, but 

 are always closely surrounded by the calcareous mass." He considers it 

 possible for the parasite to bore its canal by mechanical force in the 

 horny fibres of sponges, in the way that similar parasites make their way 

 through the ceU -membranes of Confervas and other plants. 



Finally, this short history would be incomplete without the interesting 

 notice by Mr. H. Moseley which was contributed to the Eoyal Society 



^ Eose, Quart. Joum. Microsc. Soc. 1855, no. x. p. 7, " On the Discovery of Parasitic 

 Borings in Fossil Pish-scak^s" (read June 1854). (Plate in toL iii. plate i.) 

 t Sitzungsb. d. k. Akad. d. Wiss., December 1858, Eand mii, no. 28. 

 X Proc. Eoy. Soc. June 9tb, 1859, vol. x. 



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