Definition: ‘Winter,’ occurs only once in the Rigveda, but often in the later texts. Zimmer is inclined to trace differences of climate in the Rigveda: he thinks that certain hymns, which ignore winter and insist on the rains, indicate a different place and time of origin from those which refer to the snowy mountains. It is, however, quite impossible to separate parts of the Rigveda on this basis. It is probable that that text owes its composition in the main to residents in the later Madhyadeśa; hence the references to cold and snow are rather a sign of local than of temporal differences. It is otherwise with the later expansion of the three into four seasons, which represents clearly the earlier advance of the Indians (see Rtu). The śatapatha Brāhmana describes winter as the time when the plants wither,"the leaves fall from the trees, the birds fly low and retire more and more.