I \i kGl S 77 



. hat like /« f triih regard /<> <In- tra 



probably not directly transmitted J 



.\ 



In tin- three geralologt \ teroceras, Agassiceras, and Oxynotia 



we End the same laws of ai ind catagenesis The psiloceran-like or 



the immediate progenitors or proximate radicals <>t' 



• and genera in the direct line of descent, but when 



is forms began to appear, and progression changed inl ssion, 



there was inding change in the radicals. Then the reti forms 



from varieties which were themselves also proportionate!) degenerate, and 



had similar reti and geratologous charactt 



The with divergent -i«Ks and broad abdomen, which 



appeared in the young of .1 and was found in -nine adults, \\a- 



■uppressed, :m<l was replaced by a modified quadragonal form in .1 I 

 This in turn was replaced by the tendency i<» accelerate the development 

 of the trigonal convergent-sided whorl and its correlative retrogressive charac- 

 &e untubercuUted pile, low broad keel, and shallow channels, in .1 ! 5 



and denotatum. The geratologous trigonal form appeared :it an earlier 

 -. until at last in AU. CottenotV it took possession of 

 tin- earliest nealogic staj 



retrogression of form in the series of Bpecies may often 1"' compared 

 with parallel pathological series of individuals, which maj be made within a 

 i : id dwarfed forms, much smaller than most of the 



healthy adult specimens of its own Bpecies. These last, though bo much 1 

 ordinarily showed no -i'_ r n- of old age, while the dwarfs were completely ch 

 nile metamorphoses. Much smaller but similarly dwarfed gpecimei 

 curred in A . with even more compressed and prematurely 



whorl-. 1 A remarkable series of these dwarfs, from which the two Bgures 

 • in tin- notes were drawn, is to be found in the Museum of Stutt- 



• of the inpletely geratologous specimens is not 



■>• of the largest, which itself is not of average Bize, as stated above. 

 i ui-oii of these dwarfs with the more involute varieties of l B 



and the adult o: i ( -Imu- that the) cannot have been connected by 



inheritance. They were evolved independently of these geratoli 

 tonus, and I aui not calling upon the imagination to till any blanks when I 

 of them as homoplastic morphological equivalents of Aft. imp* 



i n hardly be doubted thai the gerato rms, when 



found a- dwarfed varieties within a species, are the products of the unfavorable 



nirroundings, or, in other words, that the) are i •■ or lest 



individuals. I • parallelism in every respect with A 



' that we can attribute with great probability the 



origin of all such forms to similar pathologicnl en 



u ••. n _• I to it may be remarked that the quad- 



■ 



