SB 10.52.2

saṁvīkṣya kṣullakān martyān
 paśūn vīrud-vanaspatīn
matvā kali-yugaṁ prāptaṁ
 jagāma diśam uttarām
Synonyms: 
saṁvīkṣya — noticing; kṣullakān — tiny; martyān — the human beings; paśūn — animals; vīrut — plants; vanaspatīn — and trees; matvā — considering; kali-yugam — the Age of Kali; prāptam — having arrived; jagāma — he went; diśam — to the direction; uttarām — northern.
Translation: 
Seeing that the size of all the human beings, animals, trees and plants was severely reduced, and thus realizing that the Age of Kali was at hand, Mucukunda left for the north.
Purport: 

There are several significant words in this verse. A standard Sanskrit dictionary gives the following English meanings for the word kṣullaka: “little, small, low, vile, poor, indigent, wicked, malicious, abandoned, hard, pained, distressed.” These are the symptoms of the Age of Kali, and all these qualities are said here to apply to men, animals, plants and trees in this age. We who are enamored of ourselves and our environment can perhaps imagine the superior beauty and living conditions available to people in former ages.

The last line of this text, jagāma diśam uttarām — “He went toward the north” — can be understood as follows. By traveling north in India, one comes to the world’s highest mountains, the Himālayan range. There one can still find many beautiful peaks and valleys, where there are quiet hermitages suitable for austerity and meditation. Thus in Vedic culture “going to the north” indicates renouncing the comforts of ordinary society and going to the Himālayan Mountains to practice serious austerities for spiritual advancement.