NASSA. 1 !> 



" The study of varieties in the genus A'as.sa," says Mr, Marrat, 

 " has aciiieved one iireat object — it luis taught us the whole 

 details of the plan on which the external ornamentation of shells 

 has been elaborated. The whole of the variation, from the 

 smooth shell to the most elaborately-sculptured examples, is 

 plainly to be seen as etfected through almost imperceptil)le 

 gradations. 



"Variation through the whole kingdom of Nature is the rub' 

 and not the exce])tion. It is the prejudice exhibited l)y Scientists 

 against so much that is clear and distinct, that creates the con- 

 fusion. If studied as it exists, the whole group is manifestly 

 develo})ed, step by step, and we see the wisdom, power and 

 beneticence of the Maker. 



"The greater part of the works on Natural History are 

 written in the closets of the authors, who both theorise and 

 copy to a large extent; but, unfortunately, they copy errors as 

 well as facts. 



"The study of variation has oi)ened up a subject so vast in 

 its dimensions that the mind almost shrinks from the task of 

 estimating it. In every direction variation extends, in every 

 way variation seems to ramify, until we gaze and wonder if 

 there be any end. 



" Instead of 200 species, at least 8000 varieties are before me. 

 and the end appears nearly as far oft' as ever. Taking a careful 

 surve}' of the shells under consideration, and noting more par- 

 ticularly the common forms and the changes presented by them, 

 we are enabled to form an estimate of the enormous number 

 likely to be met with, if we persevere in our work of collecting 

 varieties. 



" Species are and have been made by men in their ignorance. 

 Had they known the alliances, it would have been impossible 

 for them to have committed such mistakes as are to be found in 

 conchological books. Species have been and still arc the 

 ultimatum of scientists. It appears to me that they haAe an 

 instinctive horror of the nameless. Lamarck described the 

 Xassa sitbspinosa from shells that were subspinous, not then 

 knowing that there Avere carinated, costated, muricated, and 

 smooth varieties of it. At least six good (?) species have 

 emerged from the varieties of Lamarck's shell : N. It/rata. 



