: whatever reading was best adapted to be selected by the scribe had the best chance of being reproduced.
 The question of whether local texts were likely to form during a particular phase of textual history then comes down to the question of how mobile readings were at the time. This, in turn, rests on the question of how mobile the vectors of the viral readings were, namely the manuscripts. Epp shows that during the first few centuries of the Christian era, letters and documents could be transported far and wide with surprising speed. Nevertheless, I suggest that the principle of least effort, which is useful for understanding many human enterprises, would make it preferable to pick up a nearby exemplar rather than send for an exotic one when a copy had to be made.
 What then? Were manuscripts so mobile as to make the development of local texts unlikely? It seems that MDS maps provide a clue and at the same time give us reason to revisit a theory of the text which has fallen out of favour. The following figure shows a two-dimensional projection of the classical MDS result obtained from the Hebrews data:
 Strangely enough, there seems to be a correspondence between this map and a physical map of the Mediterranean:
 A number of broad correlations between textual clusters and early Christian population centres emerge when the MDS and physical maps are compared:
Members of the “Western” cluster (e.g. Old Latins and Vulgate) are to the west.
A great cloud of witnesses spreads across an arc encompassing the north-eastern and eastern shores of the Mediterranean. This cloud includes a number of witnesses whose textual locations correspond to their suspected geographical provenances, such as Chrysostom, the Byzantine standard text, and the Syriac versions.
The “secondary Alexandrian” cluster (A, C, 33, etc.) corresponds to Egypt.
 If the correlation between textual clusters in MDS maps and physical locations of Christian population centres around the Mediterranean rim is more than coincidental then MDS maps can be used to associate textual clusters with geographical locations. One can then speculate that the “southern” part of the great cloud should be associated with Palestine, and begin to remember something said long ago by B. H. Streeter:
If we look at the map we see at once that the Churches whose early texts we have attempted to identify stand in a circle round the Eastern Mediterranean — Alexandria, Caesarea, Antioch, (Ephesus), Italy-Gaul, and Carthage. The remarkable thing is that the texts we have examined form, as it were, a graded series. Each member of the series has many readings peculiar to itself, but each is related to its next-door neighbour far more closely than to remoter members of the series... Antecedently we should rather expect the text of any particular locality to be, up to a point, intermediate between those of localities geographically contiguous with it on either side. But the exactness of correspondence between the geographical propinquity and the resemblance of text exceeds anything we should have anticipated.
 Whereas his work on the synoptic problem remains foundational, Streeter's theory of local texts seems to have fallen by the wayside. As Metzger and Ehrman say,
Today, there are few critics who follow Streeter's method in all of its particulars. Most recognize that the Caesarean text, for example, cannot be firmly established ... and that, in fact, apart from the text of Alexandria, it is difficult to find clearly demarcated textual families associated with the various major sees of early Christendom.
 Does Streeter's theory of local texts deserve to be shelved? Even though his postulated “Caesarean” text-type seems to have disintegrated, his expectation of an association between textual complexion and geographical locality seems to be supported by the MDS maps.
 These maps have some puzzling features, however. For instance, why is the Ethiopic in the “north-eastern” region? Why is the Armenian in the “secondary Alexandrian” cluster? And what about P46 and B? The location of the Ethiopic is