A SHORT ACCOUNT OF THE ATTACKS OF THE 

 TEREDO NAVALIS, AND CHELURA TEREBRANS 

 UPON GREENHEART {NECTANDRA RODKEl) AND 

 SNEEZEWOOD {PTEROXYLON UTILE) TIMBERS. 



By R. H. Hammersley-Heenan, Mem. Inst. C.E. 



[Read 28th November, 1888.] 



There is perhaps no experientie more remarkable in the abstract, 

 or interesting in its application, than that the greatest enemies of all 

 life — both animal and vegetable — are to be found, in many cases, as 

 organisms, infinitely small, lurking in and feeding on vital tissues, 

 which they soon destroy. A proper understanding of the conditions 

 under which such organisms exist and flourish, is of the vastest 

 importance to applied science in almost every one of its many branches. 

 In surgery the advance made in this direction appears almost in- 

 credible. 



By the aid of antiseptics the surgeon now fearlessly enters 

 portions of the human body, that a few years ago he would not have 

 dared to touch. 



Cultivators of plants now know they have enemies, which although 

 indiscernible to the naked eye, are, when examined under the 

 microscope, found to be armed with instruments of destruction, which 

 they use with merciless rapidity if left undisturbed. 



The engineer and naval architect have also long known of one or 

 two of these small enemies. They belong to a class low down in the 

 scale of life, but for all that, they work fearful destruction wherever 

 they find a home. I refer to the Teredo Navalis, the Chelura Terebrans 

 and the Limnoria Terebrans, 



The Teredo^ or the sea-worm as it is commonly called, is found in 

 wood (under sea-water) which it perforates, nearly always in the 

 direction of the grain of the timber, and lines the tunnel, or cavity, in 

 which it lives with a calcareous wall. These tunnels, and the lined 

 walls, can be easily traced and examined on the specimen pieces of wood 

 I send to illustrate this paper, and the size of the worm itself can be 

 accurately estimated. 



