THE DAWN-ANIMAL AS A TEACHER IN SCIENCE. 213 



ages_, and with reference to wliicli the production and 

 growth of this creature were initial steps. It is 

 this mystery of design which really constitutes the 

 ^'^ profound significance^^ of the foraminiferal skele- 

 ton. 



Another phenomenon of animality forced upon our 

 notice by the Protozoa is that of the conditions of life 

 in animals not individual, as we are, but aggre- 

 gative and cumulative in indefinite masses. What, for 

 instance, the relations to each other of the Polyps, 

 growing together in a coral mass, of the separate parts 

 of a Sponge, or the separate cells of a Foraminifer, or 

 of the sarcode mass of an indefinitely spread out 

 Stromatopora or Bathybius. In the case of the 

 Polyps, we may believe that there is special sensa- 

 tion in the tentacles and oral opening of each indi- 

 vidual, and that each may experience hunger when in 

 want, or satisfaction when it is filled with food, and 

 that injuries to one part of the mass may indirectly 

 afiFect other parts, but that the nutrition of the whole 

 mass may be as much unfelt by the individual Polyps 

 as the processes going on in our own bones are by us. 

 So in the case of a large Sponge or Foraminifer, there 

 may be some special sensation in individual cells, 

 pseudopods, or segments, and the general sensation 

 may be very limited, while unconscious living powers 

 pervade the whole. In this matter of aggregation of 

 animals we have thus various grades. The Foramini- 

 fers and Sponges present us with the simplest of all, 

 and that which most resembles the aggregation of 



