17 November 2009

Another 19th century painting of terrestrial gastropods


This is Tafel XI from an 1889 paper by E. von Martens*. The drawing of the live snail on the bottom represents a Helix asemnis venusta, a species of southwestern Turkey and the nearby Greek Islands.


The previous 19th century painting of terrestrial gastropods was here.

*E. von Martens. 1889. Griechische Mollusken. Archiv für Naturgeschichte 55:169. (Full text from the Biodiversity Heritage Library.)


xoggoth said...

Never noticed before but snails all seem to coil the same way. ie clockwise if you look from the pointy side with the head at right. Is there some reason for that?


Most snail shells are dextral, which means that when the shell is held with its apex up & aperture facing the observer, the aperture will be on the right. There is no explanation for why dextral species are more numerous than sinistral species.

xoggoth said...

I bet the sinistral ones are much more evil than the others.

Joel VanDerMeulen said...

Hmmm, today in my biology lecture my instructor mentioned how they discovered the gene that is responsible for sinistral or dextral development, and stated it is possible to change which way the shell develops. So I guess the allele for the shell being Dextral is dominant.