In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: All of the rats in the saline - treated epileptic control group developed SRS , whereas none of the BMC - treated epileptic animals had seizures in the short term ( 15 days after transplantation ) , regardless of the BMC source .
### Output Text:
All of the rats in the saline - treated epileptic control group developed SRS , whereas none of the BMC - treated epileptic animals had seizures in the short term ( 15 days after transplantation ) , regardless of the BMC source . 