492 REPORT ON ZOOLOGY, MDCCCXLIV. 



of the entire mass not being surrounded by any cyst is not 

 opposed to the view of its consisting of Echinococci, because, 

 in rare instances there is no doubt that Echinococci do occur 

 not encysted. In the second case also an Echinococcus- 

 colony indubitably existed, as is evident from the vesicles of 

 various sizes contained one within the other, and from the 

 progeny pullulating on their internal surface. But Goodsir 

 should have described more precisely the ova, which he says 

 he saw between the membranes of the vesicular bodies. 

 Just as little does the Reporter dare to express an opinion 

 respecting the FUarice which Goodsir thinks he observed in 

 the gelatinous envelop of the vesicular bodies. In the figure, 

 at all events, no Nernatoid worm is recognisable ; the 

 central granular portion of these filamentous bodies, 

 explained by Goodsir as Filarice, was, perhaps, not black, 

 but colourless, and appeared black by transmitted light 

 under the microscope, whilst the same object under re- 

 flected light would have presented a chalk-white colour. 

 In stating the colours of microscopic objects, naturalists have 

 in general paid too little attention to the conditions under 

 which the object is regarded, particularly whether by trans- 

 mitted or reflected light. 



Goodsir furthermore (Report of the Fourteenth Meeting 

 of the British Association for the Advancement of Science, 

 held at York, 1841. London, 1845 ; Notices, p. 67) ex- 

 presses himself with respect to Entozoa inhabiting cysts, 

 and remarks, quite correctly, that a cyst, the internal sur- 

 face of Avhich secretes a nutrient fluid for its parasites, 

 produces, in time, a substance of too great consistence, in 

 which the inhabitants are killed and entombed. But that 

 Goodsir had still no very clear notion with respect to 

 Echinococcm ho minis, is evident from the three species of 

 Cyst-worms instituted by him under the names Acephalo- 

 cystis simplex, monroi, and armatus. The first species is 

 said to contain only a few youug cysts ; in the second the 

 mother-cyst (germinal membrane) is stated to be subdivided 

 by a fibrous tissue into many compartments, which are 



