244 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 84 



from that time on until he received his appointment in the Paris 

 Entomological Station his writings related mainly to the anatomy and 

 physiology of certain marine articulates and (toward the end of this 

 period) to certain biological points concerning wasps. 



He has always been a rather prolific writer. In 1894 and 1895 his 

 attention was drawn to certain Dipterous enemies of the small grains, 

 and in his studies of the parasites of these insects he became greatly 

 interested in the biology of the parasitic Hymenoptera. 



By this time he had married. I have seen a photograph of a group 

 of workers and their families at the Marine Biological Station at 

 Roscofif, Brittany, of which Lacaze Duthiers was the eminent Di- 

 rector. Marchal and his wife were in this group. I forget whether 

 they were married at that time, or were about to be married. 



At all events, when I first visited him, in the summer of 1902, he 

 and his wife with four small children were living in a charming little 

 villa at Fontenay-aux-Roses near Paris, and I think that his widowed 

 mother was living with them. Shortly before this he had published 

 his paper entitled " The Dissociation of the Egg into a Large Number 

 of Distinct Individuals and the Evolutive Cycle of Encyrtus fiisci- 

 collis." I had read this paper, and had strong doubts concerning it. 

 1 had reared many egg-parasites and had never found any that did 

 not issue as adults from the parasitized egg of the host. That such a 

 parasitized egg should hatch and that the eggs of the parasite should 

 be retained in the body of the issuing caterpillar — that these should 

 subdivide into a great number of competent embryos — that these in 

 time should develop into larvae, and that eventually from the single 

 egg deposited by the parasite in the egg of the host there should issue 

 a very great number of adult parasites from the caterpillar, of the 

 host — all these things seemed absolutely incredible. However, on 

 that memorable day in August, 1902, after a charming luncheon 

 which all four of the children attended, we went into his little labora- 

 tory on an upper floor and he showed me his specimens and his 

 methods. I was at once convinced of the accuracy of his observations. 

 His technique had been perfect, his scientific care admirable, and he 

 had proved beyond all question a very extraordinary point in biology. 



His sul)sequent work confirmed this earlier work, and of course it 

 is a matter of common knowledge that it has been confirmed and 

 carried further by Silvestri in Italy, by Patterson in Texas, and by 

 Leiby and Hill working for the Ikireau of Entomology. 



By the time I returned to the United States, Silvestri's large paper 

 on this general sul)ject had been iniblished, and I wrote a long article 

 for the journal Science describing these conclusions and also the 



