I beleive in the perfect indefiniteness & frequently the vast length of the interval between the formation of any one bed & that which rests upon it

I beleive any amount of beds may be intercalated almost any where not only between any two formations, but anywhere in any formatⁿ. & that the ordinary ideas of Geologists as to contemporaneity will have to be greatly expanded—

I am therefore prepared to treat with very little respect the argument ag^t. you derived from missing links.²

When you have anything approaching to a continuous series of beds you have the links, moreover, when you get species ranging through a great series of beds they do vary. Calymene Blumenbachii for instance is found in both Upper & Lower Silurian, but Salter says that those found in Lower Silurian vary so much from the Wenlock ones that he has doubted their being the same species & was inclined to give them another name.³ So Baillie & I have arrived at the conviction that Spirifer Verneuilli. S. disjunctus & S. strictus are mere varieties of one species, that found in the Lower beds having been christened Verneuilli.⁴ So Terebratula hastata has about 30 synonyms & it is very likely that some of the varieties are of greatly diff^t. ages.⁵

Your theory accounts for just so much of progressive improvement as we see has taken place i.e. an improvement & a multiplication & a complexity in the whole but not necessarily absolute in every step or every instance, & relative but not always absolute—