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on larvae. These data on the larvae of bivalves and echinoderms, diverse in 

 methods, conditions, and accuracy of studies requires systematization. The 

 next step to understanding the ecology of life cycles as a whole would be to 

 present the entire descriptive and experimental material in the conceptual 

 framework of any model of the life cycle — r, /^-strategy — or other more 

 adequate models of the strategy of the life cycle, providing a vivid picture of 

 its "economy" in conditions of variable biotic factors. This step has been 

 done. In 1989, we published a book entitled "Reproduktivnaya strategiya 

 morskikh dvustvorchatykh moUyuskov i iglookozhikh" [Reproductive Strat- 

 egy of Marine Bivalves and Echinoderms] (Kasyanov, 1989). We leave it to 

 the reader to judge whether our step was in the right direction and whether 

 it was successfiil. 



