1^0. 647] AUTOPHORIC TRANSPLANTATION 557 



the retraction often practised by the oculist is easy, and 

 even regeneration of the lens has been occasionally re- 

 corded (see Literature, Przibram, Kegeneration, 1909). 



Unlike the eye of vertebrates, arthropod eyes are not 

 suitable for our method of transplantation. They usu- 

 ally protrude much too far from their socket to be kept 

 in place after their replantation solely by the friction or 

 other forces exerted by the host. A discovery of Walter 

 Finkler has nevertheless put us in position to avail our- 

 selves of the autophoric method for furnishing insects 

 with a new pair of eyes. This young student, having had 

 the opportunity of seeing the results in vertebrates, sev- 

 ered the head of several types of hexapodes from the 

 thorax and, replanting it on its own body or on that of 

 another decapitated individual, observed its retention by 

 the friction and blood clot. There can be no doubt that 

 also in these cases function is restored, all reactions of 

 the normal animal reappearing after,a few days or weeks, 

 and the tissues joining quickly. Finkler has worked on 

 the larval, pupal and imaginal state. Perhaps the most 

 astonishing fact is the ready response of the imago to 

 such operations in spite of its lack of regenerative power. 

 But also in this case, as in the higher vertebrates, we shall 

 have to take into account that in our experiments no other 

 processes of reparation are called into play than those 

 of slow physiological regeneration, which still persist in 

 adult organisms. At any rate, in all the tissues of adult 

 insects severed connections are quickly restored, when the 

 organs are left in place, as Finkler could prove. His 

 experiments on autophoric transplantation in insects will 

 be extended to appendages, whilst P. Weiss, Koppanyi, 

 Finkler and Wiesner are also occupied with autophoric 

 replantation in parts of the vertebrate body other than 

 the eyes. 



Summary 



1. Well-defined parts of the animal bo.ly that may be 

 easily detached at the same coiinoetinu' points can be re- 

 placed by similar new organs under folhjwing conditions: 



