NOTES

משנה ו

Background: This is the first משמנה that addresses כלאי בהמה, forbidden combinations of animals, which will be more thoroughly addressed in פרק ח.  This איסור prohibits both interbreeding and teaming different types of animal together.

כלב הכפרי והשועל - The רמב"ם describes כלב הכפרי as a hound (a hunting dog) raised in towns; the רע"ב says it was a small breed, closer in size to a fox, which may explain why the תנא thought they could be confused with each other even though foxes look distinctively different than dogs; רש"י in (.בבא קמא (פ states first that it was a small dog, but provides an alternate description that says it was a large dog; תוספות חדשים prefers the first of these explanations as consistent with our משמה pairing it with the fox.  However, from the גמרא in (:יבמות (נט it appears more likely that it was a large animal, at least in the context there ("ורבעה כלב כופרי מאחריה").  Indeed, רש"י there states only that it was a large dog used to hunt wild animals, and does not mention the possibility that it was a small dog.  If in fact what this משנה is referring to such a large dog, than שועל here may actually mean a jackal, which would more closely resemble a large dog (as proposed in כלאי זראים והרכבה), rather than a fox, which is different in both in size and appearance.

העיזים והצבאים - While there is no question that עיזים refers to goats, the definition of צבי as used by the משנה and גמרא is not necessarily deer, as is usually assumed - in fact it is a subject of disagreement between רש"י and רבינו תם in (:חולין (נט.  There, the גמרא states that the horns of the צבי are not forked, which is, of course, inconsistent with the horns of deer.  רש"י suggests that the צבי of the גמרא might actually be a species of wild goat native to the European Alps, known in German as steinbock; ר"ת deals with this difficulty by employing a גרסא that has the גמרא state that the צבי did have forked horns.  Because goats, with which the צבי is paired with in this משנה, do not resemble deer at all, תוספות אנשי שם views this משנה as supporting the position of רש"י.  However,  while our משנה is not consistent with ר"ת, it is also unlikely that the תנא was familiar with steinbock, a species of wild goat found only in the European Alps, much less saw fit to devote a part of the משנה to such a rare animal.  While it is possible that צבי refers to the nubian ibex, a mountain goat that is indigenous to the middle east, this is unlikely because יעלים, which is in the next pair listed in the משנה, is widely regarded to be such  wild goat.  Thus, it is most likely that, as suggested by כלאי זראים והרכבה, the משנה is referring to gazelles.

משנה ז

אין מביאין אילן באילן - This is referring to different types of fruit trees that are grafted together, or fruit trees grafted with trees that do not bear fruit (e.g. apple in orange or pear in oak).  However different types of non-fruit bearing trees may be grafted together (e.g. oak in pine) as all non-fruit-bearing trees are considered a single variety (רע"ב).

וירק בירק  - This too is only אסור with different types of vegetables (e.g. cucumber in radish), but one may graft to plants of the same type (e.g. tomato in tomato).  

רבי יהודה מתיר ירק באילן - According to תוספות יום טוב his reason is that such a graft would not produce a new, hybrid fruit or vegetable, even if the rootstock would sustain the scion grafted into it.