802 EEPOET— 1893. 



collecting: the mud and levigating off the fine silt, the organisms are collected by 

 sucking them up from among the coarser debris, treated with 95 per cent, spirit, 

 picked out singly with a mounted needle from the debris which had necessarily 

 been sucked up with them, dried over oil of vitriol, and pounded. The impalpable 

 powder (moistened with alcohol, as water wets it with difficulty) is extracted 

 with water. 



The watery extract shows the following properties : — 



1. It hydrolyses starch paste in a neutral solution, but much less readily in 

 presence of dilute mineral acids. It converts the starch rapidly into erythro-dextrin, 

 but the formation of a sugar which will reduce alkaline copper solution is somewhat 

 tardy. 



2. It has no action whatever on thymolised milk in two days. 



3. It liquefies fibrin rapidly iu presence of dilute acids, but it is only after 

 prolonged action that a distinct biuret reaction reveals the presence of pepsin. 



4. It only attacks fibrin very slowly, and partially in neutral solution, and 

 indol and skatol are not formed. 



The enzymes present, therefore, resemble ptyalin and pepsin ; tri/psin, rennin, 

 and steapsin (or pialyn) appear to be absent. 



About 1,000 individuals furnish one grain of dry substance. Two series of 

 experiments were made with about this quantity of material each time. It is 

 proposed to repeat and complete the research in the autumn. 



8. Report on the Physiological Action of the Inhalation of Oxygen. 



See Reports, p. 551. 



Department op Zoology. 



1. On the Luminous Organs of Ce;phalopoda. By William E. Hotle. 



It was recorded by Verany so long ago as 1851 that certain spots on the body and 

 arms of the rare and beautiful cuttlefish {Histioteuthis Bonelliana) gave out a phos- 

 phorescent light in the dark, but no subsequent observer has been fortunate enough 

 to have the opportunity of confirming his observation, or indeed of procuring a 

 specimen of the species. The allied form {Histioteuthis Hiippellii), which has spots 

 of precisely similar appearance, has been several times examined, though never 

 in the living condition. During the early part of the present year Professor 

 Joubin, of Eennes, published an account of his examination of the structure of 

 these organs. My own investigations have been made upon Histioteuthis Hiippellii, 

 upon another rare species, Calliteuthis reversa, and upon two species of Enoplo- 

 teuthis, a genus remarkable for having a number of the suckers developed into for- 

 midable hooks. 



As regards the first, the specimen at my disposal was not in a very satisfactory 

 state of preservation, so that I can say no more than that my results on the whole 

 agree with those of Joubin. 



In Calliteuthis, a genus not far removed systematically from Histioteuthis, the 

 organs are essentially similar iu distribution and in appearance to the naked eye, 

 and, as might therefore be expected, they are very similar in structure. The most 

 noticeable differences are that the distinction between the lens and the transparent 

 cone of Joubin is scarcely marked, and that the mirror situated anteriorly to the 

 main part of the organ is scarcely marked. These points may, however, be due to 

 the sections having been made from a very young specimen. 



In Enoploteuthis the appearance and structure of the organ are very different. 

 When the surface of the body is examined under a pocket-lens there are seen 

 among the ordinary chromatophores larger roimd spots, each having a pearly centre 

 surrounded by a ring of pigment, and usually somewhat raised above the general 

 level of the epithelium. These spots are confined to the ventral aspect of the 

 animal, but are found on the mantle, funnel and arms, as well as roimd the eyes. 



