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reached these little organisms the development of some fomi of 

 sexual apparatus, of Ai'cliegonia and Antherizia has betrayed the 

 dual character. If we trace down the animal to his original cell 

 nucleus, we find an organism continually multiplying itself by 

 fission — division into two — and thus here we have the same 

 difficulty in saying that unity is reached. Even the mineral 

 world fares no better, since aU the modern chemists have agreed 

 to represent the smallest portion of free matter by a molecule 

 -composed of two atoms. 



When however we come to the consideration of Number 

 Two, there is no difficulty in finding examples. All animated 

 nature is dual. The smallest, simplest animal we know is 

 symmetrical, having two sides alike. The Pleurobrachia may 

 be taken as the type of the form of which the Annulosaj are built 

 up ; a mere jeUy-like ball with two long tentacles, one placed on 

 each side. Such an animal, having legs instead of tentacles, a 

 distinct ganglion in the centre, haemal and digestive processes 

 forms the typical " somite." A number of these somites joined 

 together forms an annulose animal, and the junction of three or 

 more rings into a head or thorax determines the difference of 

 Insect, Arachnid, or Ecrustacean. An annulose animal is therefon; 

 a continued multiple of two, and even those organs which are 

 apparently simple are really dual. Thus the butterfly's trunk is 

 composed of two pieces — the bee's sting has a double, or 

 symmetrical sheath. The Vertebrata may probably be looked 

 upon as two annulose structures arranged longitudinally ; the 

 one represented by the brain and spinal column, the other by the 

 ventral portion of the body with the digestive, haenal, and 

 sympathetic nervous processes — but whether this be so or not, 

 the dual character is distinct throughout. We have two ears, 

 two eyes, two nostrils ; our brain, our heart, our dental arrange- 

 ments are double, and though this paper is not intended to deal 

 with metaphysical questions, few wUl doubt that in the jiresence 

 of an involuntary muscular action contrasted with a potent 



