1899] BRITISH BOTANY 163 



from Egypt with rice. It is suggested that its presence near Manchester 

 is due to an introduction of the seeds along with Egyptian cotton, and 

 this view is supported by the fact that the Manchester plant resembles 

 Egyptian specimens in a certain anatomical detail of the leaf-structure. 

 The new Altra was growing attached to the stem and leaves of the 

 Najas, and may have been similarly introduced ; but, so far, the genus 

 Pithophora has not been recorded from North Africa. 



Polemics and a Parasite. 



The Zoologischcr Anzeiger for July 3 contains an article by Professor 

 W. M. Wheeler entitled " J. Beard on the Sexual Phases of Myzostoma" 

 (pp. 281-288), which is a fine example of polemical discussion. 

 We all like a fair fight, even if we won't admit it ; and perhaps these 

 zoological tilts are like the combats of male spiders in this, that neither 

 party is wounded. Wheeler criticised Beard, and Beard criticised 

 Wheeler, and the bystanders were edified ; and we cannot but say 

 that the edification continues as Wheeler returns to the charge. Our 

 only doubt is as to the wisdom of using words that have a moral 

 connotation, words like " garble " and " misrepresent," which we see 

 in the paper before us. A more philosophic note is struck when Mr. 

 Wheeler expresses the hope that " continued controversy may induce 

 some student (we omit the adjective conscientious) who has an op- 

 portunity of working at the Naples Station or at the French or 

 Japanese sea-side laboratories, to undertake a renewed study of the 

 reproductive organs of the various species of Myzostoma." 



But what is the dispute about ? Beard holds that M. glabrum is 

 dimorphic, the species being represented by hermaphrodite individuals 

 and by dwarf complemental males. The latter are dorsicolous, that is, 

 they are attached to the dorsal surface of the large hermaphrodite 

 individuals which in turn adhere to the peristome of Antedon rosacea. 



From a comparative study of several species representing the 

 morphological extremes of the genus Myzostoma, Wheeler concluded 

 that M. glabrum is monomorphic, each individual being from the first 

 hermaphrodite, i.e. possessing both ovaries and testes, and being like 

 other members of the genus (notably M. cirriferum and M. alatum ) 

 protandrous, then hermaphrodite, and ultimately more or less hystero- 

 gynic. " In other words, the functional male phase (Beard's com- 

 plemental male) passes into the functional hermaphrodite phase as 

 soon as the first ova mature, and the functional female phase begins 

 with the atrophy or disappearance of the testes. The cysticolous and 

 endoparasitic species of the genus tend towards a condition in which 

 the functional male and female phases overlap but little, thus exhibiting 

 only a brief functional hermaphrodite, phase {M. eremite*), or these 



