Sir, - In responding to the letter from Dr Connor Long, (November 3rd) I note with interest that he is adept in the time-honoured technique of debating: when one is losing a point one moves the goalposts. In this case he is now ignoring the fact that his original letter, which I responded to, attacked the Green Party with a wide selection of examples.However, that he has chosen to focus in a somewhat myopic way on the definition of a food, in this case sugar, made from a genetically engineered crop, should not be allowed to trivialise the debate. What is at issue is: at what stage in the food production chain do we draw the line in describing a food as "genetically engineered"? In essence this is a clash between the rarefied world of scientific academia and the real world, as I am well aware from the debates on the subject in the European Parliament's Committee on Research and Technology.It is a well-known scientific fact that sugar does not contain genes, yet it is also well-known in genetic science that when foreign genes are placed in a plant, they alter the fine-tuning of the DNA resulting in unpredictable side-effects, already being manifested in foods produced from such "tampered" sources. I am happy to consider any form of wording which will convey this to the consumer, for example, "Round-Up Residue Sugar".Genetic engineering is a new scientific activity. Unlike previous breeding practices, genetic techniques are deliberately used to break the safety net of nature and cross the species barriers evolved over millennia. The unpalatable fact for scientists is that as a science it is neither certain nor precise.As to the definition of pesticide, within the European situation, herbicide, fungicide, insecticide and rodenticide are all aggregated under the one description of pesticide by Eurostat.A further complexity is the fact that the tests on Round-Up are showing many of the effects of a pesticide rather than a herbicide. - Yours, etc.,Nuala Ahern MEP,Greystones,Co Wicklow.