This, as I understand it, is one of those situations where the more arcane aspects of grammar and linguistics intersect. First of all, let's tackle the ii endings. Why are there two i's? To answer that question you have to understand what is happening when Latin compounds are formed. And for purposes of this discussion, the combination of a foreign - i.e. not Latin - name with a Latin case ending is a compound. When Latin forms compound words, it generally uses the letter i as the connective vowel. (Greek on the other hand used the letter omicron (note that in both Latin and Greek, these connective vowels are short; i.e. the short omicron rather than the long omega, in the case of Latin, the short i. That is important to remember, because it can influence the position of the accent for those who follow the 'antepenult' rule for accent). So, back to Latin compounds. They use the short i to connect two word stems to form a new word. Thus, if you want to combine the word aesculus (horse chestnut) and the word for foliage, folius, you get aescul (the stem of aesculus) + the connective vowel i + folius to get aesculiflius. There are minor complications with words which have a different stem in the oblique cases, or words which use noun forms in the possessive (frowned upon), but the above is a good generalized picture of what happens. In the case of a word derived from a non-Latin personal name, you follow the same procedure: you "Latinize" it by adding an i to the "stem". In, for instance English personal names, which do not have stems different from the nominative form, you simply add an i to "Latinize" the name. For instance, with the name Smith, you write smithi- . The i- at the end of the this word indicates that there is more to come, depending on whether you want to combine it with another Latin stem (poor form to mix Latin words and non-Latin words in the same compound) or simply add a Latin case ending. What we want to do is add a Latin case ending. That takes care of the first of the two i's. Now on the that Latin case ending. If the word Smith refers to a masculine Smith, and you want to use the traditional form to commemorate Mr. Smith, you use the masculine singular genitive form which just happens to be another i. Thus, you have Smith + connective vowel i + masculine singular genitive i to give smithii. Note on pronunciation (Jane, be still): how you pronounce these words is your business. However, there is something to be said for consistency, and it irks me to hear people pronounce the first of those i's as e as in easy and the second of those i's as eye. Thus, smith-ee-eye. The two i's differ in length (the connective i remember is short, the genitive i is long), but they are both the same letter otherwise. I prefer to pronounce them both with the e sound (remember the Great English Vowel Shift), the first one short, the second long. It's curious that even people with no experience of linguistics instinctively seem to pronounce the first i as e in easy; I have no idea why they switch to the 'eye' sound for the second one. The other question you ask, Diana, has more to do with esthetics than grammar proper. Vowels which follow or precede other vowels are subject to change in Latin and other languages. Two together pose one sort of problem; three together are intolerable. When a non-Latin personal name ends in a vowel, it is usually Latinized without the stem vowel and, if the masculine singular genitive form is wanted, one i is added to the vowel which ends the non-Latin name. Thus Lilium grayi, not L. grayii. I would like to comment on one other thing you said. "I thought from my extremely distant memories of Latin that the "i" ending means "of" or "from" or "belonging to" or something of that sort," Yes, it does. Historically (in this case I mean pre-Linnean) usage was in a simple grammatical sense. Because scientific names were not standardized, each scholar tended to use his (were there any hers? ) own names. And when reading these old books, you have to keep in mind that although they sometimes look like modern binomials, they were intended simply as Latin. Because scholars used their own naming systems, commentators frequently found it necessary to write something like Caprimulgus rayi to indicate "the concept Caprimulgus as defined by Ray". In modern times this usage is obsolete; modern usage had degenerated into a vanity show. These modern genitive name forms are purely honorifics. There is more to this, but the above will get you started. Jim McKenney Montgomery County, Maryland, USA, USDA zone 7, where I wonder how many of you know about Roland Wilbur Brown.