W. COLE ON A TAKASITE OF HUMBLE BEES. 97 



The mature Sphcerularice vary somewhat in size ; but the full 

 grown ones are about an inch in length, of cylindrical shape, with 

 a uniform diameter of about T g-th of an inch. They are white in 

 colour, and more or less transparent, often so much so, that the 

 simple internal organs can readily be traced through the skin. 

 Their most striking peculiarity, and one which suggested the 

 name of the genus, 'is the possession of a large number of round, 

 wart-like bodies, or spherules, arranged in regular order oyer the 

 entire surface of the body, giving it a very pretty appearance 

 under a low power. On an average, there appear to be about 800 

 of these warts on each worm ; they are about T ^oth of an inch in 

 diameter, and project T q 4 - t to y^^ths of an inch from the surface 

 of the body. Each of these spherules is filled with granular 

 matter, with which is mixed, in some cases, larger refractive 

 globules, apparently of fat. Some are more dense than others, 

 and these darker spherules are found principally in the neigh- 

 bourhood of the vulva. By the action of alcohol or Beale's 

 carmine fluid, this granular matter shrinks more or less away 

 from the transparent walls of the spherule, forming an almost 

 opaque mass, in the centre of which is generally seen a kind of 

 nucleolus which is always intensely tinged by the carmine. The 

 spherules appear to have no communication with the interior of 

 the body, and their function is entirely unknown.* 



The skin of the animal is a transparent membrane in which 

 ordinarily no indications of structure can be discerned. In some 

 of the smaller, and less mature worms, however, I have been able 

 to trace a division of the skin into rectilineal areas, in the centre of 

 each of which lies a spherule. Sir John Lubbock, who had an 

 opportunity of examining the worms during the winter, when they 

 were very young, describes each spherule as a cell with a distinct 

 nucleus and boundary walls. The divisions I have noticed are, in 

 all probability, the remains of the walls of these cells, which 

 become more and more obscure as the animal develops. I have 

 examined the skin with and without the use of reagents, under a 

 ^th inch, but have not been able to discover the slightest trace of 



* Dr. Matthews has suggested to me, with considerable probability, 

 that these wart-like bodies may subserve nutrition as absorbents ; in 

 which case their hemispherical form would be of great service by pre- 

 senting a much larger surface to the nutritive perivisceral fluids of the bee, 

 than if merely on a level with the general contour of the body of the 

 Entozoon. — W. C. 



