My dear Sir/

I ought ere this to have replied to your last¹— especially as more than a fortnight has elapsed since I completed, so far as this neighbourhood is concerned, my enquiries about the white Cats. My neighbour M^rs. Ellis of Hoddesdon² has three white cats all of which are, and always have been stone deaf and thus far your original statement is confirmed. But—per contra—M^r. Bedingfield the proprietor of a well known horticultural & fishing rendezvous for Cockneys in the adjacent parish of Nazing³ has five white cats and a kitten all, like my cat, fully endowed with the faculty of hearing. When I tell you that in answer to his call they came rushing from all parts of the premises (with 4 black cats) more like a flight of tame pigeons than any thing else, and clustered around his legs, mewing for food, there could not remain a shadow of a doubt, than these 9$\frac{1}{2}$ pussies were in every sense, wide awake.⁴

I will now answer your questions in regard to my Saffron Hill quondam Parishioners the rats.⁵ My attention was drawn to the blindness of the rats by my Sexton, and I presume that he could only have heard it from the workmen, as his profession lay rather with dead Xtians than dead animals, but as the poor man is himself dead, I cannot clear this point up. It is quite possible that the rats may have been temporarily blinded, as you suggest, by sudden exposure to the light, and if this be the usual effect upon cave-animals suddenly brought into the glare of day, it w^d. I suppose be very unsafe to assert that this had not been the result in the present case. All that I now recollect about the appearance of the eyes is that they were of that peculiar white or ashy hue which one commonly sees in the blind. But I will make further enquiry, whenever an opportunity offers, from some of the contractors for our city Sewers who may possibly be able to give reliable & valuable information. For any thing that I have said, you are most welcome to use my name, but I should think that my information about the rats is scarcely matter-of fact enough for your purpose.

I am almost afraid that in what I am about to write I shall get out of my depth and betray my ignorance. However I will venture to state what has occurred to me viz—that your whole theory of the origin of Species might possibly find its best confirmation in observations of Microscopists upon Infusorial Animalcules and especially upon the rudimentary spores such as Euglena Protococcus &c. And for this reason especially that within a few hours even, one has the opportunity of watching the developement of generation after generation; and because observations upon such forms of life patiently prolonged over a series of years would most likely detect some minute structural change of sufficient amount & regularity to form a law. I should very much like to hear what such observers as the authors of the recent Microgr. Dictionary, M^r. Griffiths & Henfrey would think of this idea.⁶ It would be easy to calculate what the proportion would be between 5 years observation of the Generations of an infusorium or a spore, as compared with any of the longest recorded observations of the developement of any of the larger animals or plants—and what would be the chance of detecting an organic change.—

I hope I am making my meaning clear. At all events I think that I understand myself—   And it was your book which put the idea into my mind in connection with observations I have made upon Volvox Globator,—of the following nature. I never yet found V^x. in any pools in which under altered circumstances of temperature & moisture I did not find the individual animalcules or rather green spores of wh. V^x is composed. In the Pools on Clapham Common & Norwood Hills in 1857 I found large q^s. of the V^x well developed— but in 1858 I found nothing in the same pools but the Separate spores