Extract all of the dates mentioned in this paragraph and list them using bullets in the format {Date} - {Description}

The Carolina Biological Supply Company was founded in 1927 by Dr. Thomas E. Powell Jr., a young geology and biology professor at Elon College (now Elon University). During the 1920s, science teachers had to collect most of the materials they used in their classes and laboratories, which took considerable time away from their primary responsibilities. Like other teachers, Dr. Powell spent much of his own time in the field gathering specimens for his classes. Because he usually got more than he needed, he sold the surplus to his colleagues. His efforts grew into Carolina Biological Supply Company, as Powell foresaw a need for his collecting abilities in the coming years.

• 1927 - This is when the Carolina Biological Supply Company was founded.
• 1920s - During this time period science teachers had to collect most of the materials they used in their classes and laboratories, which took considerable time away from their primary responsibilities.