I would like to thank everyone who has contributed to this thread. I have learned a great deal from the various thoughts and views, and a few things have been clarified in my thoughts. When I asked "what is masculinity and femininity", I was thinking in terms of generalities and not specifics. Some have discussed specifics at length, which is fine with me because it helps to understand how their thought processes are working in arriving at their conclusions. The identity side of things remains a difficult one to analyse however. I think that part of this difficulty arises out of terminology and the way it is used not only by our community but by society generally. Some observations are:

People, generally, tend to use the word "gender" when what they are referring to is "sex"
Additionally, they tend to use the word "sex" when they are discussing any form of genital intimacy.
People tend to think of "masculinity" and "femininity" as being descriptions of man and woman respectively.

Gender is a grammatical term for the allocating of words into separate categories. Those categories are masculine, feminine and neutral. In English, this is mostly limited to pronouns such as he, she and it, or his, her's and its. In French, it extends to articles, which in English are the and a, but in French are le and la, or un and une. Thus inanimate objects are given a gender in French. This allocation of things was probably loosely based on which sex made the most use of them, or tended to build them etc. but in modern society these distinctions are extremely blurred. Over the ages, gender has come to be synonymous with sex, perhaps because of the inaccurate uses of the word sex. However, the original meaning of gender was masculine, feminine or neutral, and not man and woman, or male and female. Over the ages, every society has determined what characteristics it considers to be masculine and which ones feminine, based on its observations and expectations of each sex. Thus the tendency has been to equate masculinity with the male and femininity with the female.

The major change in thinking in recent years, is that gender is not so much a factual division of humanity into two genders, in the same manner as sex, but rather a sliding scale of how each individual identifies themselves. Additionally, one's place on this scale is also variable depending on mood, situation etc. For this reason, gender identity is a very difficult subject to comprehend. I identify as male, because I tend to think in terms of sex. I possess all the physical attributes of the male and thus I never feel that I am female. My personality contains a fairly high recognition of my feminine qualities, which I think every male possesses to a degree, and thus I have discovered that crossdressing is a means of expressing those feelings and emotions. I feel somewhat feminine (based on my understanding of those qualities), but I don't feel like a woman because I lack the physical attributes. To me this is my sexual identity, no matter how I am dressed.

I don't know what my gender is. I feel masculine and my masculinity dominates my femininity. There was some discussion about "association" and "dissociation" as perhaps explaining some of this. As pointed out, we don't mean in a split personality sense, but simply what we have come to associate as being masculine or feminine. Because of this and the equating of gender to sex, some may feel their sense of their masculinity versus their femininity represents their gender, while others, namely the crossdressers feel that this can not alter their identification as their sex. It is a very interesting theory, but I remain somewhat confused on that aspect of TG.

Veronica