While the trichromatic theory makes clear some of the processes involved in how we see color, it does not explain all aspects of color vision. The opponent-process theory of color vision was developed by Ewald Hering, who noted that there are some color combinations that people simply never see. For example, while we often see greenish-blue or blueish-reds, we do not see reddish-green or yellowish-blue.
Spay and Neuter Average Costs. The average costs of a spay or neutering procedure is $100 or $ 150. However, the costs of the surgery may be anywhere between $50 and $500.The price may depend on several factors including: 1  The method used for the spaying; presently there are 2 methods employed: the traditional method using a scalpel and the laser beam procedure. The method used for the spaying; presently there are 2 methods employed: the traditional method using a scalpel and the laser beam procedure. 2  The laser neutering procedure is costlier than the traditional surgery. 3  The location of the clinic may also be a factor that influences the costs.
It is more expensive to spay a cat who is either in heat or who is already pregnant. At the time of writing (February, 2013), I decided to call up 5 local (Australian) veterinary practices to find out how much they charge to spay a female cat.The prices ranged from $195.00 to $250.00, with an average cost of $223.80.paying the female is usually more expensive than neutering the the male as it is a more complex surgery. However, most veterinarians are aware of the importance of desexing household pets and do their best to keep costs down. Speak to your vet if you have any concerns about cost.