278 On the Relatioyis of the TFas/* and Rhipiphorus. 



all those Zoosporece in which hitherto zoospores only have 

 been found. 



The following is a short summary of the results of this 

 paper : — 



1. In the division of the ZoosporecK there are to be found 

 motile brood-spheres which appear in the fonn of zoospores. 



2. The resting brood-spheres are more or less abnormal 

 forms of the zoospore, devoid of cilia. 



3. The colourless anterior end of the brood-spheres of Alg», 

 the " canal-cell " of the higher Cryptogams, and the " fila- 

 mentary process" of Ph^enogams are structm-es which are 

 morphologically identical with the so-called mouth, germ- 

 spot, or, wdiat is the same thing, tliej^o^ of the zoospore. 



4. By analogy to the phenomena of total and partial seg- 

 mentation in animal ova, it happens in plants that sometimes 

 the entire mass of the brood-sphere is appropriated to the 

 formation of the embryo, sometimes only a portion of it ; in 

 the latter case there occurs an entire (?) or partial casting-oif 

 of the colourless foot of the brood-sphere, which casting-off 

 occurs sometimes before (as in Vaucheria^ Coleochcete, and 

 Salvinia), sometimes after (?) impregnation (as in Phaeuo- 

 gams). 



5. The remarkable phenomenon that the zoospore is the 

 morphologically fundamental state of the reproductive organs, 

 is an argument for the embryological unity of the vegetable 

 kingdom, and shows that there is a morphological as well as 

 a histological point of contact between it and the animal 

 kingdom. 



XXX. — A last word in Reply to Dr. Chapman and Mr. Fre- 

 derick Smith on the Relations of the Wasp and Rhipiphorus. 

 By Andrew Murray. 



The subject has now been so fully ventilated that further 

 discussion seems unnecessary. We have reached that stage 

 when little more can be said on either side until further 

 observation shall have given us fresh materials to argue from. 

 The discussion which has taken place, however, has been of 

 good service in clearing away irrelevant matter, and showing 

 us where the pinch really lies. I trust that Dr. Chapman 

 may have every success in his researches during the ensuing 

 summer ; and should he succeed in proving me to be in the 

 wrong, I promise to make him my fullest and handsomest 

 acknowledgments. 



To Mr. Smith I have still an answer to n)ake. 



