586 ORDER ABDOMINALIA. 



doubt it can be protruded through the minute orifice, and 

 voluntarily moved about. Out of a male, ^ths of an 

 inch in length, I dissected a penis, which, when not 

 stretched, measured ^ths of an inch in length ; when a 

 portion was pulled between two needles, it could be 

 stretched to apparently three times its former length, and 

 I should think that this organ could be extended by the 

 animal to, perhaps, even the T ~ths of an inch, — that is, to 

 between eight and nine times its own entire length ! The 

 use of this enormously elongated penis obviously is, that 

 the spermatozoa of these males, which are so extremely 

 small in size, compared to the female, should all be con- 

 veyed within the sack, and none be lost. It should be 

 borne in mind, that the whole male, including every part, 

 is scarcely larger than a single ovum, of which sometimes 

 sixty have to be impregnated by only two or three males. 

 In a full-grown female, the distance from one of the attached 

 males to the middle of the orifice leading into the sack, is 

 about the -r^ths of an inch, equal to the length of the coiled 

 up, not-extended penis : the further distance from the orifice 

 of the sack to an ovum lying at the bottom of the sack, 

 would be almost -^oths of an inch, so that the spermatozoa 

 have to pass a distance of T ^ths of an inch from the testis of 

 the male to the lower ova. I believe two thirds of this dis- 

 tance would be passed safely along the probosciformed penis. 

 The resemblance between the male of Cryptophialus 

 and of Alcippe is truly surprising ; and is the more won- 

 derful, considering the great dissimilarity of their pupae. 

 Hardly any characters can be pointed out in which these 

 males differ, excepting such as might have been thought 

 of only specific value, namely the relative proportions of 

 the different parts, and mere external shape. The pe- 

 duncle growing a little after the metamorphosis, in the 

 male of Alcippe, and the prolongation of its capitulurn with 

 the included oblique ligamentous fibres, are the greatest 

 differences. Having fully remarked, under Alcippe, on the 

 wonderfully rudimentary condition of these males, destitute 

 as they are of so many parts and organs, I will here say 

 nothing further on these singular creatures, destined to dis- 

 charge their spermatozoa, die, and be succeeded by a fresh 

 set of short-lived male successors. 



