HYDRO-MEDUSA. 79 



In the next illustration of self-division the two resultants seem 

 to be more truly individual in character than those which we 

 have just been talking about; but a similar phenomenon in 



had noticed that the medusae no longer broke loose from the head, and that at 

 the same time they did not develop quite so fully as earlier in the season. A 

 little later I found that they were still more undeveloped ; the feelers were mere 

 conical projections, and the bell was much deeper, like a thimble in shape ; but 

 what most particularly struck me was that the proboscis was much larger than in 

 the free medusae. In the course of a few days I obtained an abundance of 

 Coryne upon whose heads all the medusa-like bells possessed an enormous pro- 

 boscis (fig. 42, pr, p/' 1 ,^/- 2 ) ; in fact, large enough to fill the whole cavity of the 

 bell and project far beyond it. The greater bulk of the proboscis consisted of 

 closely crowded eggs, imbedded beneath its wall. The feelers (/) were scarcely 

 if at all developed, and the canals (cA, ch l ) were in a more or less evanescent 

 state. In fact the whole organization of the bell corresponded in every essential 

 respect with similar organs of another Hydroid, (Tubularia, chapter xiv.,) which 

 never possesses them in a more fully developed state, but loses them by a pro- 

 cess of withering away, after the eggs have developed into moving bodies similar 

 to itself, and escaped. 



No one would hesitate to call the egg-producing bell of Tubularia a reproduc- 

 tive organ, nor would it seem illogical, therefore, to insist that the identical organ 

 of Coryne should be looked upon in the same light. That it develops, at an 

 earlier season, to a higher degree, and becomes a freely moving body, does not 

 make it any the less a reproductive organ ; for if it did, where then are these 

 organs in the mean while ? Acknowledging that when in its free state it has an 

 individualistic character, yet nevertheless it is the reproductive organ, and the 

 only one, as truly so as the always persistent, medusa-like, egg-bearing organ of 

 Tubularia. 



The reproductive organ of Rhizogeton (fig. 38) is identical in character with 

 that of Coryne, but its development never carries it beyond that of a simple 

 sac, without canals or feelers. Now between the degree of development of the 

 reproductive organ of Rhizogeton and that of the highly complicated Coryne, 

 there are all possible shades of gradation, many of which I have shown to 

 occur even in the latter animal, and, as a consequence, there are likewise as 

 many degrees of individuality, zyit is insisted that these egg-producing bodies are 

 not parts of the hydra organism, but essentially and actually separate individual 

 medusae. This conclusion is inevitable, for it cannot stand to reason that on 

 the one hand the mere fact of breaking loose from the hydra constitutes the in- 

 dividuality, whilst on the other hand those meduso-genitals which, although de- 

 veloping to a scarcely less degree, remain attached, are consequently rendered 

 mere appendages, or parts of the organism of the hydra. 



