The President's Address. By Dr. C. T. Hudson. 179 



Thus, for instance, the trophi of the Melicertidse appear in Pom- 

 pholyx, one of the Triarthridm. Nay, more, it is easy to point out 

 Kotifera that hear some striking characteristics of two or three other 

 genera, or even of two or three other famihes. Microcodon clavus, 

 for example, has the central mouth and double ciliary wreaths of the 

 Fhsculariidse, the eye of a Notommata, the trophi of a Diglena, and 

 the foot of a Monostyla. Again, Pterodina patina has the corona 

 of Philodina, the lorica and transversely-wrinkled retractile foot of 

 Brachionus, the foot-ending of a young Khizotan, and the mastax of 

 the Melicertidse. Then there is Mr. Thorpe's new Australian Floscule, 

 which swims freely like one of the Ploima, has the buccal cup and 

 wreath of Floscularia, the dorsal eye of Notommata, and the body 

 and forked foot of Proales. 



To sum up, we may say that in the female Eotiferon, the 

 corona, head, foot, toes, appendages of the trunk, antennae, eyes, and 

 contractile vesicle vary down to almost absolute extinction ; while, if 

 we include the male in our survey, we must add that even the 

 whole of the alimentary tract may disappear also. Moreover, the 

 characteristics of the various groups interlace in so many ways, that 

 no organ — nor indeed any combination of two or three organs — can 

 be relied upon to determine with certainty an animal's true position. 



Two conclusions are, in consequence, irresistibly forced on us : 

 the first, that the Rotifera, from Pedalion to Alhertia, are related by 

 descent; the second, that their curious habitats, wide dispersion, and 

 great variations in their structure are due to causes that have been at 

 work for a very long period of time. 



One other fact has also been made clear in this review : namely, 

 that the British Eotifera give a very fair idea of the whole class. 

 No doubt there are many foreign species, and some of these are very 

 remarkable, and of great interest ; but the greater number fall readily 

 enough into the divisions that contain our own species. 



And, indeed, it is a fortunate thing that we can here, at our own 

 doors, study so many typical forms from life. For what books or 

 drawings can give us the delight which we derive from observing 

 the animals themselves ? 



To gaze into that wonderful world which lies in a drop of water, 

 crossed by some atoms of green weed ; to see transparent living 

 mechanism at work, and to gain some idea of its modes of action ; 

 to watch a tiny speck that can sail through the prick of a needle's 

 point; to see its crystal armour flashing with ever- varying tint, its 

 head glorious with the halo of its quivering cilia ; to see it gliding 

 through the emerald stems, hunting for its food, snatching at its 

 prey, fleeing from its enemy, chasing its mate (the fiercest of our 

 passions blazing in an invisible speck) ; to see it whirling in a mad 

 dance to the sound of its own music, the music of its happiness, the 

 exquisite happiness of living — can any one, who has once enjoyed this 

 sight, ever turn from it to mere books and drawings, without the 

 sense that he has left all fairyland behind him ? 



