69 



dilating fluid. Parasites wliicli have a habitat very different 

 from what they enjoyed in a free state must have gradually 

 arrived at the condition in which they can enjoy it. The more 

 the condition varies fi-om the normal free condition, the more 

 the animal is modified to withstand and profit by that change of 

 condition. The least modified are the ectoparasites who inhabit- 

 ing the outside of animals, are surrounded by the same respiratory 

 medium, and often catch their own prey, not being parasites to 

 the extent of feeding on their host, although many ectoparasites 

 are mean enough to do that. One Cimex lenticularis, seems to 

 have begun a semi-parasitic life within the last few centuries, its 

 nearest relatives being vegetable feeders. Of endo parasites, 

 parasites inhabiting the inside of their host, some, as Leptodera, 

 are only occasionally parasitic, and as a rule they are recruited 

 from the lower orders of the animal kingdom, these animals 

 being more adaptable to change. The changes an animal which 

 inhabits the interior cavity of another has to undergo when he 

 first enters it from the surrounding medium are numerous — loss 

 of light, change of temperature, and change of chemical com- 

 position and specific gravity in its surrounding medium. These 

 changes are sometimes however undergone by non-parasitic 

 animals ; and in the cases of parasites if the animal can once 

 sustain the shock and get acclimatized, the condition is extremely 

 favoiu^able for its growth, and multiplication. It has no longer 

 to avoid enemies, or to seek food, so all reason for exertion being 

 lost, its limbs, and organs of sense, often atrophy, and its whole 

 energy is given to the purely vegetative functions of increasing 

 and multiplying ; the result is a considerable retrogression fi-om 

 the free types in all the higher functions. In fact Parasitism is 

 the reverse of the struggle of existence, the sharper the struggle 

 the more vigorous, and energetic do the survivors tend to become, 

 whilst in the too favourable circumstances of the endo parasite 

 the animal tends to become dull, shapeless, and lazy, often 

 scarcely distinguishable from a piece of lifeless jelly. 



'Numerous illustrations of the various points were given, and 

 diagrams lent by the authorities of Owens College, Manchester, 

 were displayed. 



RECITAL: SHAKESPEARE'S "OTHELLO." 



By J. G. FLEMING. November 2nd, 1886. 



For the convenience of members brief notes on the history of 

 the piece and its production, together with an ovithne of the 

 tragedy under its five Acts were provided. Mr. Fleming made a 

 good selection of the parts for recital, and very successfully ren- 



