63 DARWINISM TO-DAY. 



im Gehororgan der Wirbeltiere, welcher bekanntlich erst in der 

 Klasse der Fische auftritt. Dieser dritte Kanal ist den beiden 

 andern vollig gleich, hat Crista, Ampulle, Macula etc., ist aber 

 spater entstanden ; die namlichen zufalligen Variierungen, die 

 stattfanden bei der Entstehung der beiden ersten Kanale, mussten 

 viele Generationen spater ganz genau in derselben Art sich wieder- 

 holen ! Dass diese Variierungen wieder auftreten, dies erklart die 

 Darwinsche Lehre nicht ; denn die Selektion kann ja keinen Ein- 

 fluss auf die Variierung ausuben. 



"Aehnlich sind die Resultate der Kowalevskyschen Untersuch- 

 ungen iiber fossile Huftiere zu betrachten, welche sich auf die im 

 Lauf der phylogenetischen Entwicklung stattgehabten Umwand- 

 lungen des Extremitatenskelettes dieser Tiere beziehen. Hier kann 

 bekanntlich eine allmahlich eintretende Verringerung der Anzahl 

 der Metatarsal- nnd Metakarpalknochen sowie der Phalangen 

 verfolgt werden. Diese Verringerung tritt zuerst an den hintern, 

 erst spater an den vordern Extremitaten auf!" 



24 A moth, Pliryganidia calif ornica, whose larvae live abundantly 



on the oak trees in California, shows very clearly how a conspicuous 



Example of mal- disadvantage does not seem to interfere much with 



adaptation in egg- successful life; for the "success" of this moth is only 



laying habit of too well proved by the serious injuries which it pro- 



Phryganidia cah- duceSj because of its great numbers, on the beautiful 

 fornica. .... ^ 



trees it infests. For several years the live-oaks and 



white oaks of the Santa Clara Valley were defoliated to a dangerous 

 extent. The life history of the moth is told in detail in "The 

 Californian Phryganidian," by Kellogg and Jack, Proc. Cal. Acad. 

 Sci., Ser. 2, Vol. V, pp. 562-570, 1895. From this account I quote the 

 following: "Although most abundant on the live-oaks (Q. agrifolia}, 

 the larvae attack other oaks. We have found them on Qitercus 

 lobata, Q. kelloggii, Q. dnmosa, and Q. douglasii. The live-oaks in 

 this vicinity begin to put out new leaves about January I, but in 

 the case of many of the trees badly defoliated by the larvae in the 

 autumn, new leaves appeared much earlier than the first of Janu- 

 ary. The wintering of the insect in a larval condition is only possi- 

 ble in the evergreen oaks, and they are thus the natural and usual 

 host of the pest. At the time of the hatching of the first of the 

 autumn brood of eggs (latter part of November), the leaves of the 

 deciduous oaks begin to fall. But, oddly, the eggs were found to 

 be deposited on the leaves of both the white oak and Douglas's oak 

 (deciduous oaks), and the larvae hatched only to die of starvation. 

 By this suicidal means the pest aids in depleting its own numbers. 

 The new leaves of the deciduous oaks appear about April i. before 

 the eggs for the summer brood of larvae are deposited. These eggs, 



