Royal Institution of Great Britain. 415 



seven different kinds of units in the colony, all referable, however, to 

 one type. 



A Flustra, or " sea-mat," grows upon shells, and resembles a piece 

 of pale brown seaweed. Each organism is an animal colony ; but its 

 units, which may number several thousands in one organism, are not 

 structurally connected together like those of the zooj)hytes, but are 

 contained each in a separate cell. 



The Tceniada, or tapeworms, consist each of a linear series of 

 similar "joints." Each "joint" is in reality comparable to the 

 unit of zoophyte or " sea-mat ;" for it is essentially a distinct mem- 

 ber of a colony, and possesses a complete set of generative and 

 other organs, and is produced from the head and neck by budding. 

 According to Hackel, starfishes and sea-urchins are each compound 

 or " colonial " animals. Structurally, it is provable that each ray 

 of a starfish corresponds with worm-structure in broad details. The 

 Nais and other freshwater worms produce young forms by a new 

 head being budded out amongst their joints. There is here seen a 

 tendency to become doubly " colonial ;" inasmuch as the single 

 worm is typically a " colonial " animal, and the new head-develop- 

 ment causes this compound body to detach a new colony. 



Amongst insects, the Aphides, or plant-lice, produce by veritable 

 " budding " new generations, and the queen-bee does not fertilize 

 those eggs which are destined to become " drone " beea. Thus the 

 homology of an egg with a " bud" appears demonstrable. 



It is the business of philosophy to correlate and arrange facts to 

 form a harmonious and scientific system. The philosophy of biology 

 leads us firstly to define an "individual" structurally as a being 

 whose parts and organs are so closely and intimately connected, that 

 separation of even a limited structural area means disintegration of 

 the individual as a whole. Physiologically, an " individual " animal 

 or plant is the total development of a single egg or seed. As the 

 whole zoophyte, sea-mat, and tapeworm arise each from a single 

 egg, each, in toto, is an " individual." The separate units of each are 

 named " zooids." A new personality does not enter into the life- 

 cycle of any animal or plant until a new egg or seed has been pro- 

 duced. Even in the case of the Hydra, although the buds become 

 detached and, to all appearance, are each as truly an " individual " 

 as their parent, they possess nevertheless no true personality. They 

 are merely units or zooids of a colony ; they were produced by bud- 

 ding, and as such are not " individuals " but parts of an " indivi- 

 dual." If we assumed that the buds of a zoophyte or tapeworm 

 were " individuals," we might with equal correctness speak of the 

 joints of a lobster or worm as " individuals " likewise. Even in 

 human structure itself there are to be seen traces of a fundamentally 

 " colonial " nature. The tissues of the highest animals are but ag- 

 gregations of cells. As such, they have a semi-independent consti- 

 tution ; and there are certain protoplasmic cells (e. g. the white or 

 amoeboid corpuscules of the blood) which roam independently at 

 will through the body, and possess powers of movement exactly 

 resembling those of the Amoeba and its kind. 



