528 The Blennies : Blenniidas 



the interior of which is coated over with mucus. There are 

 no secretory glands embedded between these membranes, and 

 these sacs are probably merely the reservoirs in which the fluid 

 secreted accumulates. The absence of a secretory organ in 

 the immediate neighborhood of the reservoirs (an organ the 

 size of which would be in accordance with the quantity of fluid 

 secreted), the diversity of the osseous spines which have been 

 modified into poison organs, and the actual communication 

 indicated by the foramen in the sac lead me to the opinion 

 that the organ of secretion is either that system of muciferous 

 channels which is found in nearly the whole class of fishes, and 

 the secretion of which has poisonous qualities in a few of them, 

 or at least an independent portion of it. This description was 

 made from the first example; through the kindness of Captain 

 Dow I received two other specimens, and in the hope of proving 

 the connection of the poison bags with the lateral-line system, 

 I asked Dr. Pettigrew, of the Royal College of Surgeons, a 

 gentleman whose great skill has enriched that collection with 

 a series of the most admirable anatomical preparations, to lend 

 me his assistance in injecting the canals. The injection of the 

 bags through the opening of the spine was easily accomplished; 

 but we failed to drive the fluid beyond the bag or to fill with 

 it any other part of the system of muciferous channels. This, 

 however, does not disprove the connection of the poison bags 

 with that system, inasmuch as it became apparent that if there 

 be minute openings they are so contracted by the action of the 

 spirit in which the specimens were preserved as to be impassa- 

 ble to the fluid of injection. A great part of the lateral-line 

 system consists of open canals; however, on some parts of the 

 body, these canals are entirely covered by the skin; thus, for 

 instance, the open lateral line ceases apparently in the supra- 

 scapular region, being continued in the parietal region. We 

 could not discover any trace of an opening by which the open 

 canal leads to below the skin; yet we could distinctly trace the 

 existence of the continuation of the canal by a depressed line, 

 so that it is quite evident that such openings do exist, although 

 they may be passable only in fresh specimens. Thus likewise 

 the existence of openings in the bags, as I believed to have found 

 in the first specimen dissected, may be proved by examination 



