[After describing how he had just come back from a nine months' cruise)—First and foremost, my dear mother, I must thank you for your very kind letter of September 1848. I read the greater part of it to Nettie, who was as much pleased as I with your kindly wishes towards both of us. Now I suppose I must do my best to answer your questions. First, as to age, Nettie is about three months younger than myself—that is the difference in OUR years, but she is IN FACT as much younger than her years as I am older than mine. Next, as to complexion she is exceedingly fair, with the Saxon yellow hair and blue eyes. Then as to face, I really don't know whether she is pretty or not. I have never been able to decide the matter in my own mind. Sometimes I think she is, and sometimes I wonder how the idea ever came into my head. Whether or not, her personal appearance has nothing whatever to do with the hold she has upon my mind, for I have seen hundreds of prettier women. But I never met with so sweet a temper, so self-sacrificing and affectionate a disposition, or so pure and womanly a mind, and from the perfectly intimate footing on which I stand with her family I have plenty of opportunities of judging. As I tell her, the only great folly I am aware of her being guilty of was the leaving her happiness in the hands of a man like myself, struggling upwards and certain of nothing.
As to my future intentions I can say very little about them. With my present income, of course, marriage is rather a bad look out, but I do not think it would be at all fair towards Nettie herself to leave this country without giving her a wife's claim upon me…It is very unlikely I shall ever remain in the colony. Nothing but a very favourable chance could induce me to do so.
Much must depend upon how things go in England. If my various papers meet with any success, I may perhaps be able to leave the service. At present, however, I have not heard a word of anything I have sent. Professor Forbes has, I believe, published some of Macgillivary's letters to him, but he has apparently forgotten to write to Macgillivray himself, or to me. So I shall certainly send him nothing more, especially as Mr. Macleay (of this place, and a great man in the naturalist world) has offered to get anything of mine sent to the Zoological Society.
[In the paper mentioned in the letter of March 21, above ("On the Anatomy and Affinities of the Family of the Medusae"), Huxley aimed at] "giving broad and general views of the whole class, considered as organised upon a given type, and inquiring into its relations with other families," [unlike previous observers whose patience and ability had been devoted rather to] "stating matters of detail concerning particular genera and species." [At the outset, section 8 ("Science Memoirs" 1 11), he states—]
I would wish to lay particular stress upon the composition of this (the stomach) and other organs of the Medusae out of TWO DISTINCT MEMBRANES, as I believe that it is one of the essential peculiarities of their structure, and that a knowledge of the fact is of great importance in investigating their homologies. I will call these two membranes as such, and independently of any modifications into particular organs, "foundation membranes."
[And in section 56 (page 23) one of the general conclusions which he deduces from his observations, is]
That a Medusa consists essentially of two membranes enclosing a variously-shaped cavity, inasmuch as its various organs are so composed,