I READ with interest the Rev Kevin Logan's Saturday Message, subtitled 'There just has to be a humorous designer somewhere' (LET, May 4).

I can understand what caused him to arrive at that conclusion because the life cycle of the Halipegus worm is certainly complicated, relying as it does on several steps to enable it to locate and dine on the snail's liver.

I agree with him, in that such a complicated life cycle has not been brought about as a result of 'mindless chance' or of 'blundering, blind nature,' but by trial and error -- millions of trials and millions of errors.

However, each successful generation of those creatures, without knowing it, contributed to its ultimate success by being a vehicle for the accommodation of ever-improving genes in the construction of its life cycle, striving to achieve that end although not conscious of doing so.

'Mindless chance' and 'blundering, blind nature' are therefore words which do not come to mind.

It is important to remember too, that Halipegus had, as you might say, all the time in the world to perfect its marvellous and mind-boggling life cycle -- millions upon millions of years, in fact. And given that period of time, just about anything can happen.

This is the core of evolution and Halipegus's remarkable life cycle was put together without the aid of a divine creator.

ALBERT MORRIS, Clement View, Nelson.