278 On the Relations of the Wasp and Rliipiphorns. 



all tliosc Zoosporeo' in wliicli liitlievto zoos|)ov(>s oiilv have 

 been found. 



The following is a short suniniaiy of the results of tliis 

 jiaper : — 



1. In the division of the Zoosporea- there arc to be found 

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



2. The restnig brood-spheres arc more or less abnormal 

 forms of the zoospore, devoid of cilia. 



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

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

 mcntary process" of Pha3nogams are structures wliieh are 

 mor])hologicallj identical with the so-called mouth, germ- 

 spot, or, what is the same thing, the^oo^ 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-spliere 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-off 

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

 occui's sometimes before (as in Vaucheri'a, Coleocha^te, and 

 Salvinia)j sometimes after (?) impregnation (as in Phajno- 

 gams). 



5. The remarkable phenomenon that the zoospore is the 

 morphologically fundamental state of the reproducti\-c 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 ivord in Rejyly to Dr. Chapman and Mr. Fre- 

 derick Smith on the Relations of the Wasp and Rhipiphonis. 

 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 liavc 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 eveiy success in his researches during the ensuing 

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

 wrong, I promise to make liim my fullest and handsomest 

 acknowledgments. 



To Mr. Smith 1 liave still an answer to make. 



