330 . SEA-SIDE STUDIES. 



is always a father and a mother, a stamen and a pis- 

 til, an element which fertilises, and an element w^hich 

 isTertilised/' The contrast is only formal. Out of the 

 substance of the parent both bud and seed are evolved ; 

 whether the product shall be a mass of cells which at 

 once develop into an organism by repeated subdivision, 

 or into eggs by repeated subdivision, will depend on 

 specific conditions ; but the essential process is the 

 same in each. The egg itself is a product, as much as 

 the embryo ; it is not a starting-point, but a station on 

 the grand junction-line of development. No one will 

 venture to assert that the process of Nutrition is other 

 than identical, whether the product evolved from the 

 blood-j^lasma be a nerve- cell, a muscle-cell, or a gland- 

 cell : different as these products are, they all issue from 

 embryonal cells indistinguishable from each other ; and 

 the law of Nutrition by which they increase is the same 

 law in all. 



The identity of the process in Reproduction is clearly 

 seen in the foUowmg results of Mr R Q. Couch's 

 observations on the Sertularian Polypes : " At certain 

 seasons of the year they produce cells (capsules) much 

 larger than those of a more permanent character. 

 These, at first, are composed of the granular pulp of 

 the stem ; afterwards the pulp becomes furrowed, and 

 finally formed into cells. After a short period they 

 separate from the parent, and undergo the process of 

 development. If these cells attain a certain size, they 

 are developed into eggs ; if they are stunted by cold, 

 they are formed into Polypes ; while if, from unfavour- 



