378 HALF-HOURS AT THE MICROSCOPE. 



that is, they are not united together to form a mass. 



A nervous system has been described in some of these Polyzoa. 

 I am not aware that the observations have yet been confirmed ; 

 still, the rapidity and consentaneity of their actions seem to render 

 its presence almost (as we might say) a matter of certainty. The 

 polypidom is described by Mr. Busk as subject to a curious acci- 

 dent : the falling off, namely, of the upper part - a fresh portion, 

 or " head," being, however, formed. A " callus," or thickened 

 scar, marks the place of union and reproduction. The specimen 

 before us appears distinctly to show marks of similar fracture and 

 repair. 



Eggs of Parasite of Common Fowl (PI. XXIII., Figs, i, 2, 3). — 

 It is rather misleading to call this as above, as it appears to imply 

 that there is only one parasite of that bird. There are, however, 

 no less than four species of lice, belonging to as many genera, to 

 which domestic fowls act the part of hosts. These are :— 



1, Goniodes dissimilis. 3, Lipetirus variabilis. 



2. Goniocotes hologaster. \.,' Menopon pallidum. 



Now, can we find out to which these belong ? 



Eggs, believed to be from Menopofi pallidum, the commonest 

 of the four, may be briefly characterised as " upwards of three 

 times as long as broad, scarcely visibly punctate." 



Such of the Lipeuris as I know are still longer in proportion to 

 their width and smooth. That leaves the maternity of these pro- 

 ductions to be settled between the two Gls in the above list : the 

 Goniodes and the Goniocotes. Does either genus possess species 

 habiting, the one the pigeon, the other the fowl? Such is the 

 case with Goniocotes I I think the probability is that these are the 

 eggs of Goniocotes hologaster. 



Such furnishes a good illustration of the slow and patient 

 process by which that accurate knowledge of things to which the 

 term " Science " is applied has to be gained, and may serve as 

 some justification of the annoyance felt by scientific men when, 

 from the want of care, or (in some cases) a direct intention to 

 mislead, barriers are erected to their progress, which at times prove 

 very difficult to clear away. It is deeply to be regretted that 

 H. Denny did not live to publish his intended work on the Eggs 



