the Origin of Intestinal Worme, 341 



commencement of spring the ova begin to appear in the pos- 

 terior joints, and by degrees fill the uteri of all the joints, till 

 they occupy those which are close to the head, when the sepa- 

 ration from the head, before described, ensues, and this last- 

 named member is left to repeat the important process. 



Thus the Bothriocephali are composite Trematods^ whose 

 composition is not the result of a ramification — the mere vege- 

 table form — like that of the Polypi, but of transverse division, 

 like an imperfect generatio fissipara transversa : their relation 

 to the Trematoda is like that of the Corals to the Hydrce ; if 

 their transverse fissures had been completed, they would have 

 resolved themselves into as many single Trematods ; just as 

 the Corals would resolve themselves into as many single hydras 

 as they have branches, if these had separated. A single joint 

 of a tape-worm will not produce an entire new organism, — ^for, 

 to the formation of this, an ova is necessary. The numerous 

 divisions of the joints is intended to produce a corresponding 

 number of bunches of ova. just as the repeated ramification of 

 plants is destined to produce new bunches of seeds. The head 

 of the tape-worm is fixed to the mucous surface, and from it 

 derives the nutritive juices required for the whole organism ; 

 in the same manner the root procures the nourishment of the 

 plant from the soil. The number of joints developed with 

 organs destined for the evolution of these germs is very great. 

 The ova having reached maturity, the joints break to liberate 

 them ; or the whole joint will be thrown off in the same way 

 as the seeds of plants are freed, sometimes one by one, some- 

 times in masses, according to the particular manner of life as- 

 signed to every species of plant and animal. And is there any 

 one who, upon the contemplation of this wonderful apparatus, 

 and the extraordinary results of its agenc}^ can for a moment 

 imagine that it is without an object or an end ? Can it be 

 supposed that these ova, substantially the same as those of the 

 higher animals, with a regular shell, formed by millions of 

 glands, in every worm, and sometimes actually containing 

 young ones, are mere fortuitous bodies, of no value or use ? 

 We consider such a conclusion nearly impossible. 



