Taxon:6 



of the gonad, it is not surprising that species with one and two ovaries 

 are placed in the same genus. It is interesting to compare the genus 

 Pratylenchus with Radopholus. Morphologically and biologically, they 

 are very similar, particulai'ly when a species of Radopholus has males 

 that do not exhibit sexual dimorphism. In this case, it is the number 

 of ovaries that becomes the primary character. This is particularly the 

 case if the observer is not experienced. By way of contrast, you are 

 all familiar with a number of present day genera that contain species 

 with one gonad and others vrith tiTO gonads. Examples may be found in 

 Psilenchus amongst the tylenchs and in many genera in the Dorylaimoidea. 

 I think this means we recognize there must be other characters that are 

 as inportant or more important than n\imber of ovaries and that these 

 characters are judged to show relationships that are of a generic 

 nature . 



Taxonomy is by no means static, new evidence is being introduced con- 

 tinuously, some of it serves to confirm previous groupings and some 

 indicates needed changes and revisions. We frequently are reluctant to 

 accept changes proposed by taxonomists. Sometimes this is due to the 

 fact that we must use new names for long established names and other 

 times we simply do not agree with the opinions of the particular worker. 

 One of the suggestions that has been made relative to new names, generic 

 changes, and revisions is, I believe, worth considering. This concerns 

 the acceptance of the opinions of the latest revisor as being valid 

 until proven otherwise. There is no need to point out the confusion 

 that is caused by the use of species names after the species has been 

 synonymized. Such usage indicates that an author has evidence to indi- 

 cate that the concerned species is not a synonym. He should present 

 this evidence at the time he removes the species from synonyn^y. 



If we are to make lasting progress in the field of nematode taxonomy, 

 we should exchange information and opinions freely. We shoiild and must 

 exchange specimens, and, most importent of all, we should have a satis- 

 factory place to deposit type material where it would be available for 

 study. Type material belongs to science and not to Individuals, and it 

 should be properly housed and cared for. A worthy objective for this 

 group and other similar groups concerned with nematodes would be to work 

 toward obtaining better facilities for a central nematode collection 

 which would also house type material. 



