Cut and pasted from my summary:
Sutton prepared a chromosomal theory of inheritance by studying grasshopper testes. He suggested Mendels factors are carried out on chromosomes. He noted that
1. He noted that chromosomes were found as homologous pairs
2. Homologous pairs of chromosomes segregate during meiosis so that each gamete receives only one chromosome of each pair
3. After fertilisation, the resulting zygote has a full set of homologous chromosomes.