350 SYMBIOGENESIS 



throughout the whole of this time. The latter condition must tend to 

 increase the number of eggs laid. In man and many domesticated 

 animals even winter has no effect in diminishing generative activity, 

 as it has in most of our wild animals. It is even possible, although 

 not proved, that the cuckoo continues to lay eggs during the winter 

 of its period of reproduction during about two months and eo lays 

 as many as twenty to twenty-four eggs (Brehm). 



The degenerative evolutionary effects of over-feeding are 

 thus again brought home to us ; but it is worth noting, in my 

 view, that the cuckoo is a rank in-feeder, and with this arise 

 important bio-economic implications which cannot by any 

 means be left out of account. 



The evolution of the cuckoo proceeds pathogenetically 

 mainly because of its biologically wrong methods of feeding, 

 and I regard its excessive sex-hunger like that of all morbid 

 stocks and of parasites generally, as emanating from the same 

 cause the same diathesis, the same " ammonisation " of the 

 blood "Blut-entmischung," as the late Dr. Lahmann called 

 it as that which is responsible for " anaphylactic " 

 phenomena, and for costly eliminative processes both physio- 

 logical and biological. 



I have treated of the biological nemesis involved in the 

 case of the cuckoo in previous volumes, and I believe I have 

 to some extent shown in this connection that the Malthusian 

 doctrine of population and that of the struggle for existence 

 require modification in the light of my bio-economic thesis, 

 which insists upon the distinction between normal and 

 abnormal phases of growth and development. 



I have been taken to task by some critics for insisting on 

 the parallel of biological ethics with human ethics, but I 

 have not seen any reasons advanced why I should not do so. 

 Prof. Eimer also sees the same fairly obvious parallelism or 

 even fundamental identity of origin, although he fails to 

 recognise the qualitative distinctions that I have drawn. Thus 

 he says : 



There are vagabonds in human society, in the lowest as well as the 

 highest, who lead in all respects a cuckoo's life our knowledge of 



